diff --git a/Libraries/Lists/FlatList.js b/Libraries/Lists/FlatList.js
index 5a98157bd0..9cc85f24ec 100644
--- a/Libraries/Lists/FlatList.js
+++ b/Libraries/Lists/FlatList.js
@@ -107,6 +107,7 @@ type OptionalProps<ItemT> = {
    *       {length: ITEM_HEIGHT, offset: ITEM_HEIGHT * index, index}
    *     )}
    *
+   * Adding `getItemLayout` can be a great performance boost for lists of several hundred items.
    * Remember to include separator length (height or width) in your offset calculation if you
    * specify `ItemSeparatorComponent`.
    */
diff --git a/docs/Performance.md b/docs/Performance.md
index 2d21d446fc..c23c06812d 100644
--- a/docs/Performance.md
+++ b/docs/Performance.md
@@ -91,6 +91,10 @@ Use the new [`FlatList`](docs/flatlist.html) or [`SectionList`](docs/sectionlist
 Besides simplifying the API, the new list components also have significant performance enhancements,
 the main one being nearly constant memory usage for any number of rows.
 
+If your [`FlatList`](docs/flatlist.html) is rendering slow, be sure that you've implemented
+[`getItemLayout`](https://facebook.github.io/react-native/docs/flatlist.html#getitemlayout) to
+optimize rendering speed by skipping measurement of the rendered items.
+
 ### JS FPS plunges when re-rendering a view that hardly changes
 
 If you are using a ListView, you must provide a `rowHasChanged` function that can reduce a lot of work by quickly determining whether or not a row needs to be re-rendered. If you are using immutable data structures, this would be as simple as a reference equality check.