diff --git a/Doc/library/tempfile.rst b/Doc/library/tempfile.rst
index 29702520367..49396b5f4bd 100644
--- a/Doc/library/tempfile.rst
+++ b/Doc/library/tempfile.rst
@@ -87,6 +87,9 @@ The module defines the following user-callable items:
    attribute is the underlying true file object. This file-like object can
    be used in a :keyword:`with` statement, just like a normal file.
 
+   On POSIX (only), a process that is terminated abruptly with SIGKILL
+   cannot automatically delete any NamedTemporaryFiles it created.
+
    .. audit-event:: tempfile.mkstemp fullpath tempfile.NamedTemporaryFile
 
    .. versionchanged:: 3.8
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index efcf7a7fb3b..8570c3ba062 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -532,6 +532,10 @@ def NamedTemporaryFile(mode='w+b', buffering=-1, encoding=None,
     Returns an object with a file-like interface; the name of the file
     is accessible as its 'name' attribute.  The file will be automatically
     deleted when it is closed unless the 'delete' argument is set to False.
+
+    On POSIX, NamedTemporaryFiles cannot be automatically deleted if
+    the creating process is terminated abruptly with a SIGKILL signal.
+    Windows can delete the file even in this case.
     """
 
     prefix, suffix, dir, output_type = _sanitize_params(prefix, suffix, dir)
diff --git a/Misc/NEWS.d/next/Library/2021-05-17-21-05-06.bpo-4928.Ot2yjO.rst b/Misc/NEWS.d/next/Library/2021-05-17-21-05-06.bpo-4928.Ot2yjO.rst
new file mode 100644
index 00000000000..359f8015821
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-05-17-21-05-06.bpo-4928.Ot2yjO.rst
@@ -0,0 +1 @@
+Documented existing behavior on POSIX: NamedTemporaryFiles are not deleted when creating process is killed with SIGKILL
\ No newline at end of file