diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index b7fbdff20cac99..1075db13da8b6f 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -388,11 +388,17 @@ def abspath(path):
     """Return an absolute path."""
     path = os.fspath(path)
     if isinstance(path, bytes):
-        if not path.startswith(b'/'):
-            path = join(os.getcwdb(), path)
+        sep = b'/'
+        curdir = b'.'
+        getcwd = os.getcwdb
     else:
-        if not path.startswith('/'):
-            path = join(os.getcwd(), path)
+        sep = '/'
+        curdir = '.'
+        getcwd = os.getcwd
+    if not path.startswith(sep):
+        if not path or path == curdir:
+            return getcwd()
+        path = join(getcwd(), path)
     return normpath(path)
 
 
diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-04-08-15-04-51.gh-issue-117639.ca4N3t.rst b/Misc/NEWS.d/next/Core and Builtins/2024-04-08-15-04-51.gh-issue-117639.ca4N3t.rst
new file mode 100644
index 00000000000000..fce709439c83e2
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-04-08-15-04-51.gh-issue-117639.ca4N3t.rst	
@@ -0,0 +1 @@
+Speedup :func:`os.path.abspath()` by up to 13% on Unix for "" & ".".