diff --git a/backend/crud.py b/backend/crud.py
index 99c4db7..d950be5 100644
--- a/backend/crud.py
+++ b/backend/crud.py
@@ -108,3 +108,70 @@ def get_unique_owners(db: Session):
             for owner in result[0].split(','):
                 owners.add(owner.strip())
     return sorted(list(owners))
+
+
+def find_duplicate_guests(db: Session):
+    """Find guests with duplicate phone numbers"""
+    from sqlalchemy import func
+    
+    # Find phone numbers that appear more than once
+    duplicates = db.query(
+        models.Guest.phone_number,
+        func.count(models.Guest.id).label('count')
+    ).filter(
+        models.Guest.phone_number.isnot(None),
+        models.Guest.phone_number != ''
+    ).group_by(
+        models.Guest.phone_number
+    ).having(
+        func.count(models.Guest.id) > 1
+    ).all()
+    
+    # Get full guest details for each duplicate phone number
+    result = []
+    for phone_number, count in duplicates:
+        guests = db.query(models.Guest).filter(
+            models.Guest.phone_number == phone_number
+        ).all()
+        result.append({
+            'phone_number': phone_number,
+            'count': count,
+            'guests': guests
+        })
+    
+    return result
+
+
+def merge_guests(db: Session, keep_id: int, merge_ids: list[int]):
+    """Merge multiple guests into one, keeping the specified guest"""
+    keep_guest = db.query(models.Guest).filter(models.Guest.id == keep_id).first()
+    if not keep_guest:
+        return None
+    
+    merge_guests = db.query(models.Guest).filter(models.Guest.id.in_(merge_ids)).all()
+    
+    # Merge data: combine information from all guests
+    for guest in merge_guests:
+        # Keep non-empty values from merged guests
+        if not keep_guest.email and guest.email:
+            keep_guest.email = guest.email
+        if not keep_guest.phone_number and guest.phone_number:
+            keep_guest.phone_number = guest.phone_number
+        if not keep_guest.meal_preference and guest.meal_preference:
+            keep_guest.meal_preference = guest.meal_preference
+        if not keep_guest.table_number and guest.table_number:
+            keep_guest.table_number = guest.table_number
+        
+        # Combine owners
+        if guest.owner and guest.owner not in (keep_guest.owner or ''):
+            if keep_guest.owner:
+                keep_guest.owner = f"{keep_guest.owner}, {guest.owner}"
+            else:
+                keep_guest.owner = guest.owner
+    
+    # Delete merged guests
+    db.query(models.Guest).filter(models.Guest.id.in_(merge_ids)).delete(synchronize_session=False)
+    db.commit()
+    db.refresh(keep_guest)
+    
+    return keep_guest
diff --git a/backend/main.py b/backend/main.py
index 279ef07..c280b1a 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -103,6 +103,32 @@ def get_owners(db: Session = Depends(get_db)):
     return {"owners": owners}
 
 
+@app.get("/guests/duplicates/")
+def get_duplicates(db: Session = Depends(get_db)):
+    """
+    Find guests with duplicate phone numbers
+    """
+    duplicates = crud.find_duplicate_guests(db)
+    return {"duplicates": duplicates}
+
+
+@app.post("/guests/merge/")
+def merge_guests(request: schemas.MergeRequest, db: Session = Depends(get_db)):
+    """
+    Merge multiple guests into one
+    keep_id: ID of the guest to keep
+    merge_ids: List of IDs of guests to merge and delete
+    """
+    if request.keep_id in request.merge_ids:
+        raise HTTPException(status_code=400, detail="Cannot merge guest with itself")
+    
+    result = crud.merge_guests(db, request.keep_id, request.merge_ids)
+    if not result:
+        raise HTTPException(status_code=404, detail="Guest to keep not found")
+    
+    return {"message": f"Successfully merged {len(request.merge_ids)} guests", "guest": result}
+
+
 # Search and filter endpoints
 @app.get("/guests/search/", response_model=List[schemas.Guest])
 def search_guests(
diff --git a/backend/schemas.py b/backend/schemas.py
index 8eebac3..08cf6d0 100644
--- a/backend/schemas.py
+++ b/backend/schemas.py
@@ -43,3 +43,9 @@ class GuestPublicUpdate(BaseModel):
     meal_preference: Optional[str] = None
     has_plus_one: Optional[bool] = None
     plus_one_name: Optional[str] = None
+
+
+class MergeRequest(BaseModel):
+    """Schema for merging guests"""
+    keep_id: int
+    merge_ids: list[int]
diff --git a/frontend/src/App.jsx b/frontend/src/App.jsx
index 240c401..6748d1a 100644
--- a/frontend/src/App.jsx
+++ b/frontend/src/App.jsx
@@ -4,6 +4,7 @@ import GuestForm from './components/GuestForm'
 import SearchFilter from './components/SearchFilter'
 import GoogleImport from './components/GoogleImport'
 import GuestSelfService from './components/GuestSelfService'
+import DuplicateManager from './components/DuplicateManager'
 import Login from './components/Login'
 import { getGuests, searchGuests } from './api/api'
 import './App.css'
@@ -13,6 +14,7 @@ function App() {
   const [loading, setLoading] = useState(true)
   const [showForm, setShowForm] = useState(false)
   const [editingGuest, setEditingGuest] = useState(null)
+  const [showDuplicates, setShowDuplicates] = useState(false)
   const [currentPage, setCurrentPage] = useState('admin') // 'admin' or 'guest'
   const [isAuthenticated, setIsAuthenticated] = useState(false)
 
@@ -117,11 +119,21 @@ function App() {
           <button className="btn btn-primary" onClick={handleAddGuest}>
             + הוסף אורח
           </button>
+          <button className="btn btn-secondary" onClick={() => setShowDuplicates(true)}>
+            🔍 מצא כפילויות
+          </button>
           <GoogleImport onImportComplete={handleImportComplete} />
         </div>
 
         <SearchFilter onSearch={handleSearch} />
 
+        {showDuplicates && (
+          <DuplicateManager
+            onUpdate={loadGuests}
+            onClose={() => setShowDuplicates(false)}
+          />
+        )}
+
         {loading ? (
           <div className="loading">טוען אורחים...</div>
         ) : (
diff --git a/frontend/src/api/api.js b/frontend/src/api/api.js
index 7eb6569..b71f334 100644
--- a/frontend/src/api/api.js
+++ b/frontend/src/api/api.js
@@ -79,4 +79,18 @@ export const updateGuestByPhone = async (phoneNumber, guestData) => {
   return response.data
 }
 
+// Duplicate management
+export const getDuplicates = async () => {
+  const response = await api.get('/guests/duplicates/')
+  return response.data
+}
+
+export const mergeGuests = async (keepId, mergeIds) => {
+  const response = await api.post('/guests/merge/', {
+    keep_id: keepId,
+    merge_ids: mergeIds
+  })
+  return response.data
+}
+
 export default api
diff --git a/frontend/src/components/DuplicateManager.css b/frontend/src/components/DuplicateManager.css
new file mode 100644
index 0000000..cb6105d
--- /dev/null
+++ b/frontend/src/components/DuplicateManager.css
@@ -0,0 +1,199 @@
+.duplicate-manager {
+  background: white;
+  border-radius: 12px;
+  padding: 25px;
+  margin-top: 30px;
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
+}
+
+.duplicate-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 25px;
+  padding-bottom: 15px;
+  border-bottom: 2px solid #e5e7eb;
+}
+
+.duplicate-header h2 {
+  margin: 0;
+  color: #1f2937;
+  font-size: 1.5rem;
+}
+
+.btn-close {
+  background: #f3f4f6;
+  border: none;
+  color: #6b7280;
+  font-size: 24px;
+  width: 40px;
+  height: 40px;
+  border-radius: 50%;
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.btn-close:hover {
+  background: #e5e7eb;
+  color: #1f2937;
+}
+
+.loading,
+.no-duplicates {
+  text-align: center;
+  padding: 60px 20px;
+  color: #6b7280;
+  font-size: 16px;
+}
+
+.no-duplicates {
+  color: #10b981;
+  font-size: 18px;
+}
+
+.duplicates-list {
+  display: flex;
+  flex-direction: column;
+  gap: 30px;
+}
+
+.duplicate-group {
+  background: #f9fafb;
+  border-radius: 12px;
+  padding: 20px;
+  border: 2px solid #e5e7eb;
+}
+
+.duplicate-info {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  margin-bottom: 20px;
+}
+
+.duplicate-info h3 {
+  margin: 0;
+  color: #374151;
+  font-size: 1.2rem;
+}
+
+.count-badge {
+  background: #ef4444;
+  color: white;
+  padding: 6px 14px;
+  border-radius: 20px;
+  font-size: 14px;
+  font-weight: 600;
+}
+
+.guests-grid {
+  display: grid;
+  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
+  gap: 15px;
+  margin-bottom: 20px;
+}
+
+.guest-card {
+  background: white;
+  border: 2px solid #d1d5db;
+  border-radius: 8px;
+  padding: 15px;
+  cursor: pointer;
+  transition: all 0.2s;
+}
+
+.guest-card:hover {
+  border-color: #667eea;
+  box-shadow: 0 2px 8px rgba(102, 126, 234, 0.2);
+}
+
+.guest-card.selected {
+  border-color: #667eea;
+  background: #f0f4ff;
+  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
+}
+
+.radio-wrapper {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  margin-bottom: 12px;
+  padding-bottom: 12px;
+  border-bottom: 1px solid #e5e7eb;
+}
+
+.radio-wrapper input[type="radio"] {
+  width: 18px;
+  height: 18px;
+  cursor: pointer;
+}
+
+.radio-wrapper label {
+  font-weight: 600;
+  color: #667eea;
+  cursor: pointer;
+  margin: 0;
+}
+
+.guest-details {
+  font-size: 14px;
+}
+
+.guest-details h4 {
+  margin: 0 0 10px 0;
+  color: #1f2937;
+  font-size: 16px;
+}
+
+.guest-details p {
+  margin: 6px 0;
+  color: #6b7280;
+}
+
+.guest-details strong {
+  color: #374151;
+}
+
+.owner-tag {
+  margin-top: 10px;
+  padding-top: 10px;
+  border-top: 1px solid #e5e7eb;
+  font-size: 12px;
+  color: #9ca3af;
+}
+
+.merge-actions {
+  display: flex;
+  justify-content: center;
+  padding-top: 15px;
+}
+
+.merge-actions .btn {
+  min-width: 200px;
+}
+
+.merge-actions .btn:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
+/* Responsive */
+@media (max-width: 768px) {
+  .duplicate-manager {
+    padding: 15px;
+  }
+
+  .guests-grid {
+    grid-template-columns: 1fr;
+  }
+
+  .duplicate-info {
+    flex-direction: column;
+    align-items: flex-start;
+    gap: 10px;
+  }
+
+  .merge-actions .btn {
+    width: 100%;
+  }
+}
diff --git a/frontend/src/components/DuplicateManager.jsx b/frontend/src/components/DuplicateManager.jsx
new file mode 100644
index 0000000..faeb17e
--- /dev/null
+++ b/frontend/src/components/DuplicateManager.jsx
@@ -0,0 +1,148 @@
+import { useState, useEffect } from 'react'
+import { getDuplicates, mergeGuests } from '../api/api'
+import './DuplicateManager.css'
+
+function DuplicateManager({ onUpdate, onClose }) {
+  const [duplicates, setDuplicates] = useState([])
+  const [loading, setLoading] = useState(true)
+  const [selectedKeep, setSelectedKeep] = useState({})
+  const [merging, setMerging] = useState(false)
+
+  useEffect(() => {
+    loadDuplicates()
+  }, [])
+
+  const loadDuplicates = async () => {
+    try {
+      setLoading(true)
+      const response = await getDuplicates()
+      setDuplicates(response.duplicates || [])
+    } catch (error) {
+      console.error('Error loading duplicates:', error)
+      alert('שגיאה בטעינת כפילויות')
+    } finally {
+      setLoading(false)
+    }
+  }
+
+  const handleMerge = async (phoneNumber, guests) => {
+    const keepId = selectedKeep[phoneNumber]
+    if (!keepId) {
+      alert('אנא בחר איזה אורח לשמור')
+      return
+    }
+
+    const mergeIds = guests
+      .filter(g => g.id !== keepId)
+      .map(g => g.id)
+
+    if (mergeIds.length === 0) {
+      alert('לא נבחרו אורחים למיזוג')
+      return
+    }
+
+    if (!window.confirm(`האם למזג ${mergeIds.length} אורחים לאורח הנבחר?`)) {
+      return
+    }
+
+    try {
+      setMerging(true)
+      await mergeGuests(keepId, mergeIds)
+      alert('האורחים מוזגו בהצלחה!')
+      await loadDuplicates()
+      if (onUpdate) onUpdate()
+    } catch (error) {
+      console.error('Error merging guests:', error)
+      alert('שגיאה במיזוג אורחים')
+    } finally {
+      setMerging(false)
+    }
+  }
+
+  if (loading) {
+    return (
+      <div className="duplicate-manager">
+        <div className="duplicate-header">
+          <h2>🔍 ניהול כפילויות</h2>
+          <button className="btn-close" onClick={onClose}>✕</button>
+        </div>
+        <div className="loading">טוען כפילויות...</div>
+      </div>
+    )
+  }
+
+  if (duplicates.length === 0) {
+    return (
+      <div className="duplicate-manager">
+        <div className="duplicate-header">
+          <h2>🔍 ניהול כפילויות</h2>
+          <button className="btn-close" onClick={onClose}>✕</button>
+        </div>
+        <div className="no-duplicates">
+          <p>✅ לא נמצאו כפילויות! כל האורחים ייחודיים.</p>
+        </div>
+      </div>
+    )
+  }
+
+  return (
+    <div className="duplicate-manager" dir="rtl">
+      <div className="duplicate-header">
+        <h2>🔍 ניהול כפילויות ({duplicates.length} מספרי טלפון)</h2>
+        <button className="btn-close" onClick={onClose}>✕</button>
+      </div>
+
+      <div className="duplicates-list">
+        {duplicates.map((dup, index) => (
+          <div key={index} className="duplicate-group">
+            <div className="duplicate-info">
+              <h3>📞 {dup.phone_number}</h3>
+              <span className="count-badge">{dup.count} אורחים</span>
+            </div>
+
+            <div className="guests-grid">
+              {dup.guests.map((guest) => (
+                <div
+                  key={guest.id}
+                  className={`guest-card ${selectedKeep[dup.phone_number] === guest.id ? 'selected' : ''}`}
+                  onClick={() => setSelectedKeep({...selectedKeep, [dup.phone_number]: guest.id})}
+                >
+                  <div className="radio-wrapper">
+                    <input
+                      type="radio"
+                      name={`keep-${dup.phone_number}`}
+                      checked={selectedKeep[dup.phone_number] === guest.id}
+                      onChange={() => setSelectedKeep({...selectedKeep, [dup.phone_number]: guest.id})}
+                    />
+                    <label>שמור אורח זה</label>
+                  </div>
+                  <div className="guest-details">
+                    <h4>{guest.first_name} {guest.last_name}</h4>
+                    <p><strong>אימייל:</strong> {guest.email || '-'}</p>
+                    <p><strong>אישור:</strong> {guest.rsvp_status}</p>
+                    <p><strong>ארוחה:</strong> {guest.meal_preference || '-'}</p>
+                    <p><strong>פלאס ואן:</strong> {guest.has_plus_one ? `כן${guest.plus_one_name ? ` (${guest.plus_one_name})` : ''}` : 'לא'}</p>
+                    <p><strong>שולחן:</strong> {guest.table_number || '-'}</p>
+                    <p className="owner-tag"><strong>מקור:</strong> {guest.owner || '-'}</p>
+                  </div>
+                </div>
+              ))}
+            </div>
+
+            <div className="merge-actions">
+              <button
+                className="btn btn-primary"
+                onClick={() => handleMerge(dup.phone_number, dup.guests)}
+                disabled={!selectedKeep[dup.phone_number] || merging}
+              >
+                {merging ? 'ממזג...' : `🔗 מזג אורחים`}
+              </button>
+            </div>
+          </div>
+        ))}
+      </div>
+    </div>
+  )
+}
+
+export default DuplicateManager