Preheat oven to 250 degrees F (120 degrees C). Lightly grease a cookie sheet.
In a large glass or metal mixing bowl, beat egg whites to soft peaks. Gradually add sugar, continuing to beat until whites form stiff peaks. Stir in vanilla and pecans. Drop mounded spoonfuls onto the prepared cookie sheet.
Bake 1 hour in the preheated oven. Turn off heat, and allow to remain in oven at least another 30 minutes, or until the centers of cookies are dry.