Chicken breast muscle was cooked to an internal temperature of 165oF by four methods: boiling, baking, sautéing and deep-frying. All cooking methods led to a decrease in formation of dialyzable iron, formed by both extraction and digestion in vitro, compared to raw muscle. After cooking most of the dialyzable iron formed results from extraction and the formation of dialyzable iron by digestion is essentially eliminated. Cooking also decreased the levels of cysteine and histidine; these losses may contribute to the loss in dialyzable iron.