diff --git a/importlib_metadata/diagnose.py b/importlib_metadata/diagnose.py
new file mode 100644
index 00000000..e405471a
--- /dev/null
+++ b/importlib_metadata/diagnose.py
@@ -0,0 +1,21 @@
+import sys
+
+from . import Distribution
+
+
+def inspect(path):
+    print("Inspecting", path)
+    dists = list(Distribution.discover(path=[path]))
+    if not dists:
+        return
+    print("Found", len(dists), "packages:", end=' ')
+    print(', '.join(dist.name for dist in dists))
+
+
+def run():
+    for path in sys.path:
+        inspect(path)
+
+
+if __name__ == '__main__':
+    run()
diff --git a/newsfragments/461.feature.rst b/newsfragments/461.feature.rst
new file mode 100644
index 00000000..bf07a91b
--- /dev/null
+++ b/newsfragments/461.feature.rst
@@ -0,0 +1 @@
+Added diagnose script.
\ No newline at end of file