diff --git a/app/src/main/java/de/bollwerk/app/ui/settings/SettingsScreen.kt b/app/src/main/java/de/bollwerk/app/ui/settings/SettingsScreen.kt
index 4e6593b..d5a002a 100644
--- a/app/src/main/java/de/bollwerk/app/ui/settings/SettingsScreen.kt
+++ b/app/src/main/java/de/bollwerk/app/ui/settings/SettingsScreen.kt
@@ -324,13 +324,33 @@ internal fun SettingsScreen(
                             )
                             Spacer(modifier = Modifier.height(8.dp))
                             OutlinedButton(
-                                onClick = viewModel::logout,
+                                onClick = viewModel::onLogoutClicked,
                                 modifier = Modifier.fillMaxWidth()
                             ) {
                                 Text("Abmelden")
                             }
                         }
                     }
+
+                    if (uiState.showLogoutDialog) {
+                        AlertDialog(
+                            onDismissRequest = viewModel::onLogoutDialogDismissed,
+                            title = { Text("Lokale Daten löschen?") },
+                            text = {
+                                Text("Möchtest du alle lokal gespeicherten Daten (Inventar, Nachrichten, …) von diesem Gerät entfernen?")
+                            },
+                            confirmButton = {
+                                TextButton(onClick = { viewModel.logout(deleteLocalData = true) }) {
+                                    Text("Löschen")
+                                }
+                            },
+                            dismissButton = {
+                                TextButton(onClick = { viewModel.logout(deleteLocalData = false) }) {
+                                    Text("Behalten")
+                                }
+                            }
+                        )
+                    }
                 } else {
                     OutlinedTextField(
                         value = uiState.loginUsername,
diff --git a/app/src/main/java/de/bollwerk/app/ui/settings/SettingsUiState.kt b/app/src/main/java/de/bollwerk/app/ui/settings/SettingsUiState.kt
index e3a5717..82e396c 100644
--- a/app/src/main/java/de/bollwerk/app/ui/settings/SettingsUiState.kt
+++ b/app/src/main/java/de/bollwerk/app/ui/settings/SettingsUiState.kt
@@ -27,7 +27,8 @@ internal data class SettingsUiState(
     val pendingQueueCount: Int = 0,
     val isSyncing: Boolean = false,
     val lastSyncTime: String? = null,
-    val openAiApiKey: String = ""
+    val openAiApiKey: String = "",
+    val showLogoutDialog: Boolean = false
 )
 
 internal sealed interface ImportResult {
diff --git a/app/src/main/java/de/bollwerk/app/ui/settings/SettingsViewModel.kt b/app/src/main/java/de/bollwerk/app/ui/settings/SettingsViewModel.kt
index 63ce673..c402c6c 100644
--- a/app/src/main/java/de/bollwerk/app/ui/settings/SettingsViewModel.kt
+++ b/app/src/main/java/de/bollwerk/app/ui/settings/SettingsViewModel.kt
@@ -7,6 +7,7 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.bollwerk.app.data.db.BollwerkDatabase
 import de.bollwerk.app.data.db.dao.PendingSyncOpDao
 import de.bollwerk.app.data.sync.ConnectionState
 import de.bollwerk.app.data.sync.WebSocketClient
@@ -22,6 +23,7 @@ import de.bollwerk.app.domain.repository.ImportExportRepository
 import de.bollwerk.app.domain.repository.SettingsRepository
 import de.bollwerk.app.domain.repository.SyncService
 import de.bollwerk.app.notification.MessagingService
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -29,6 +31,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import java.io.File
 import java.time.Instant
 import java.time.ZoneId
@@ -43,6 +46,7 @@ internal class SettingsViewModel @Inject constructor(
     private val syncService: SyncService,
     private val webSocketClient: WebSocketClient,
     private val pendingSyncOpDao: PendingSyncOpDao,
+    private val database: BollwerkDatabase,
     @ApplicationContext private val context: Context
 ) : ViewModel() {
 
@@ -227,8 +231,21 @@ internal class SettingsViewModel @Inject constructor(
         }
     }
 
-    fun logout() {
+    fun onLogoutClicked() {
+        _uiState.update { it.copy(showLogoutDialog = true) }
+    }
+
+    fun onLogoutDialogDismissed() {
+        _uiState.update { it.copy(showLogoutDialog = false) }
+    }
+
+    fun logout(deleteLocalData: Boolean = false) {
         viewModelScope.launch {
+            if (deleteLocalData) {
+                withContext(Dispatchers.IO) {
+                    database.clearAllTables()
+                }
+            }
             syncService.logout()
             webSocketClient.disconnect()
             MessagingService.stop(context)
@@ -237,7 +254,8 @@ internal class SettingsViewModel @Inject constructor(
                     isLoggedIn = false,
                     loggedInUsername = "",
                     connectionState = ConnectionState.NotConfigured,
-                    syncActivity = null
+                    syncActivity = null,
+                    showLogoutDialog = false
                 )
             }
         }
diff --git a/app/src/test/java/de/bollwerk/app/ui/settings/SettingsViewModelTest.kt b/app/src/test/java/de/bollwerk/app/ui/settings/SettingsViewModelTest.kt
index 8eb0062..16704b1 100644
--- a/app/src/test/java/de/bollwerk/app/ui/settings/SettingsViewModelTest.kt
+++ b/app/src/test/java/de/bollwerk/app/ui/settings/SettingsViewModelTest.kt
@@ -4,6 +4,7 @@ import android.content.Context
 import androidx.core.content.FileProvider
 import android.content.ContentResolver
 import android.net.Uri
+import de.bollwerk.app.data.db.BollwerkDatabase
 import de.bollwerk.app.data.db.dao.PendingSyncOpDao
 import de.bollwerk.app.data.db.entity.PendingSyncOpEntity
 import de.bollwerk.app.data.sync.WebSocketClient
@@ -53,6 +54,7 @@ class SettingsViewModelTest {
     private lateinit var fakeSyncService: FakeSyncService
     private lateinit var fakeWebSocketClient: FakeWebSocketClient
     private lateinit var fakePendingSyncOpDao: FakePendingSyncOpDao
+    private lateinit var mockDatabase: BollwerkDatabase
     private lateinit var mockContext: Context
     private lateinit var tempDir: File
     private lateinit var viewModel: SettingsViewModel
@@ -65,6 +67,7 @@ class SettingsViewModelTest {
         fakeSyncService = FakeSyncService()
         fakeWebSocketClient = FakeWebSocketClient()
         fakePendingSyncOpDao = FakePendingSyncOpDao()
+        mockDatabase = mockk(relaxed = true)
         tempDir = File(System.getProperty("java.io.tmpdir"), "test_exports")
         tempDir.mkdirs()
         mockContext = mockk(relaxed = true) {
@@ -85,6 +88,7 @@ class SettingsViewModelTest {
         syncService = fakeSyncService,
         webSocketClient = fakeWebSocketClient,
         pendingSyncOpDao = fakePendingSyncOpDao,
+        database = mockDatabase,
         context = mockContext
     )