diff --git a/docs/src/intro-python.md b/docs/src/intro-python.md
index fcb34d6264..7c9fc94dec 100644
--- a/docs/src/intro-python.md
+++ b/docs/src/intro-python.md
@@ -189,6 +189,11 @@ Playwright runs the driver in a subprocess, so it requires `ProactorEventLoop` o
 
 On Windows Python 3.7, Playwright sets the default event loop to `ProactorEventLoop` as it is default on Python 3.8+.
 
+### Threading
+
+Playwright's API is not thread-safe. If you are using Playwright in a multi-threaded environment, you should create a playwright instance per thread. See [threading issue](https://github.com/microsoft/playwright-python/issues/623) for more details.
+
+
 ## System requirements
 
 Playwright requires Python 3.7 or above. The browser binaries for Chromium,