diff --git a/src/tui/App.tsx b/src/tui/App.tsx
index 6b3a5187..281a5088 100644
--- a/src/tui/App.tsx
+++ b/src/tui/App.tsx
@@ -74,6 +74,7 @@ export function App(): React.ReactElement {
     createCase,
     killSession,
     killAllSessions,
+    killAllScreensAndClaude,
     nextSession,
     prevSession,
     sendInput,
@@ -339,6 +340,7 @@ export function App(): React.ReactElement {
         onSelectSession={handleSelectSession}
         onAttachSession={handleAttachSession}
         onDeleteSession={handleDeleteSession}
+        onDeleteAll={killAllScreensAndClaude}
         onCreateSession={handleCreateSession}
         onCreateCase={createCase}
         onRefresh={refreshSessions}
diff --git a/src/tui/components/HelpOverlay.tsx b/src/tui/components/HelpOverlay.tsx
index 61a46eed..e45c6d79 100644
--- a/src/tui/components/HelpOverlay.tsx
+++ b/src/tui/components/HelpOverlay.tsx
@@ -33,6 +33,7 @@ const SHORTCUT_GROUPS: ShortcutGroup[] = [
       { key: 'Enter', description: 'View session in TUI' },
       { key: 'a', description: 'Attach to screen (full terminal)' },
       { key: 'd', description: 'Delete/kill selected session' },
+      { key: 'D (Shift+d)', description: 'Delete ALL screens & Claude processes' },
       { key: 'c', description: 'Switch to cases view' },
       { key: 'n', description: 'Quick-start new session' },
       { key: 'r', description: 'Refresh list' },
diff --git a/src/tui/components/StartScreen.tsx b/src/tui/components/StartScreen.tsx
index 00d038cd..df922367 100644
--- a/src/tui/components/StartScreen.tsx
+++ b/src/tui/components/StartScreen.tsx
@@ -30,6 +30,7 @@ interface StartScreenProps {
   onSelectSession: (session: ScreenSession) => void;
   onAttachSession: (session: ScreenSession) => void;
   onDeleteSession: (session: ScreenSession) => void;
+  onDeleteAll: () => void;
   onCreateSession: (caseName?: string, count?: number, mode?: 'claude' | 'shell') => void;
   onCreateCase: (name: string) => Promise<boolean>;
   onRefresh: () => void;
@@ -80,6 +81,7 @@ export function StartScreen({
   onSelectSession,
   onAttachSession,
   onDeleteSession,
+  onDeleteAll,
   onCreateSession,
   onCreateCase,
   onRefresh,
@@ -168,6 +170,12 @@ export function StartScreen({
         return;
       }
 
+      // 'D' (shift+d) to delete ALL screens and Claude processes
+      if (input === 'D') {
+        onDeleteAll();
+        return;
+      }
+
       // 'c' to switch to cases view
       if (input === 'c') {
         onRefreshCases();
@@ -513,6 +521,8 @@ export function StartScreen({
                 <Text> Attach  </Text>
                 <Text color="red">[d]</Text>
                 <Text> Delete  </Text>
+                <Text color="red" bold>[D]</Text>
+                <Text> Delete ALL  </Text>
                 <Text color="yellow">[q]</Text>
                 <Text> Quit</Text>
               </Text>
diff --git a/src/tui/hooks/useSessionManager.ts b/src/tui/hooks/useSessionManager.ts
index 87997c26..79d85a08 100644
--- a/src/tui/hooks/useSessionManager.ts
+++ b/src/tui/hooks/useSessionManager.ts
@@ -156,6 +156,7 @@ interface SessionManagerState {
   createCase: (name: string) => Promise<boolean>;
   killSession: (sessionId: string) => void;
   killAllSessions: () => void;
+  killAllScreensAndClaude: () => void;
   nextSession: () => void;
   prevSession: () => void;
   sendInput: (sessionId: string, input: string) => void;
@@ -576,6 +577,44 @@ export function useSessionManager(): SessionManagerState {
     setTimeout(refreshSessions, 500);
   }, [sessions, refreshSessions]);
 
+  // Kill ALL claudeman screens and Claude processes (nuclear option)
+  const killAllScreensAndClaude = useCallback(() => {
+    // 1. Kill all tracked sessions first
+    for (const session of sessions) {
+      try {
+        execSync(`screen -S ${session.screenName} -X quit`, {
+          encoding: 'utf-8',
+          timeout: 5000,
+        });
+      } catch {
+        // Ignore
+      }
+    }
+
+    // 2. Kill any remaining claudeman screen sessions
+    try {
+      execSync('pkill -f "SCREEN.*claudeman"', {
+        encoding: 'utf-8',
+        timeout: 5000,
+      });
+    } catch {
+      // May not find any, that's ok
+    }
+
+    // 3. Kill all Claude CLI processes
+    try {
+      execSync('pkill -f "claude"', {
+        encoding: 'utf-8',
+        timeout: 5000,
+      });
+    } catch {
+      // May not find any, that's ok
+    }
+
+    setActiveSessionId(null);
+    setTimeout(refreshSessions, 500);
+  }, [sessions, refreshSessions]);
+
   // Navigate to next session
   const nextSession = useCallback(() => {
     if (sessions.length === 0) return;
@@ -684,6 +723,7 @@ export function useSessionManager(): SessionManagerState {
     createCase,
     killSession,
     killAllSessions,
+    killAllScreensAndClaude,
     nextSession,
     prevSession,
     sendInput,