diff --git a/AUTHORS b/AUTHORS
index fdcd5b6e0..821a7d8f4 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -227,6 +227,7 @@ Pedro Algarvio
 Philipp Loose
 Pieter Mulder
 Piotr Banaszkiewicz
+Piotr Helm
 Prashant Anand
 Pulkit Goyal
 Punyashloka Biswal
diff --git a/changelog/1120.bugfix.rst b/changelog/1120.bugfix.rst
new file mode 100644
index 000000000..95e74fa75
--- /dev/null
+++ b/changelog/1120.bugfix.rst
@@ -0,0 +1 @@
+Fix issue where directories from tmpdir are not removed properly when multiple instances of pytest are running in parallel.
diff --git a/src/_pytest/pathlib.py b/src/_pytest/pathlib.py
index 69f490a1d..29d8c4dc9 100644
--- a/src/_pytest/pathlib.py
+++ b/src/_pytest/pathlib.py
@@ -338,11 +338,13 @@ def make_numbered_dir_with_cleanup(
             e = exc
         else:
             consider_lock_dead_if_created_before = p.stat().st_mtime - lock_timeout
-            cleanup_numbered_dir(
-                root=root,
-                prefix=prefix,
-                keep=keep,
-                consider_lock_dead_if_created_before=consider_lock_dead_if_created_before,
+            # Register a cleanup for program exit
+            atexit.register(
+                cleanup_numbered_dir,
+                root,
+                prefix,
+                keep,
+                consider_lock_dead_if_created_before,
             )
             return p
     assert e is not None