There is mounting information on the factors which affect iron availability. Given that the total amount of iron supplied by a meal is only one of these factors, its assessment alone is a poor indicator of the adequacy of a diet with respect to iron. A model which estimates the availability of dietary iron, has been applied to the diets of 105 predominantly low socio-economic group females. The prevalence of iron deficient intakes was greater when the availability of dietary iron was calculated than was observed by an assessment of total iron intake.