diff --git a/Lib/pdb.py b/Lib/pdb.py
index f695a39332e461..8bb20b2d807154 100644
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -2008,6 +2008,8 @@ def do_quit(self, arg):
                     return
 
         self._user_requested_quit = True
+        # gh-139688 set _last_pdb_instance to None for remote debugging.
+        Pdb._last_pdb_instance = None
         self.set_quit()
         return 1
 
diff --git a/Misc/NEWS.d/next/Library/2025-10-07-18-02-53.gh-issue-139688.4ZVVQP.rst b/Misc/NEWS.d/next/Library/2025-10-07-18-02-53.gh-issue-139688.4ZVVQP.rst
new file mode 100644
index 00000000000000..486b19e254020b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-10-07-18-02-53.gh-issue-139688.4ZVVQP.rst
@@ -0,0 +1 @@
+Fix: Make ``Pdb._last_pdb_instance`` to None when ``pdb`` do_quite