The objectives of this research were to assess the bioavailability of iron in foodstuffs found in the Mexican diet, to provide data on the content of iron absorption inhibitors present in plant origin products and to assess the inhibitory effect of these compounds and of cooking on iron bioavailability; therefore, total content and bioavailable iron, tannins, phytic and oxalic acid were determined in vegetables, cereals, legumes and animal products, before and after cooking. Vegetables, although rich in iron, have poor iron bioavailability and a high content of inhibitory factors; cooking reduced the content of iron and inhibitory factors, whereas in animal products the treatment of cooking did not significantly reduce it. Iron bioavailability, phytate content and the phytate to iron molar ratio predicted poor iron bioavailability and, therefore, a negative impact on the nutritional status of people who rely on them as staple foods could be expected.