OBJECTIVE To evaluate the difference between estimations on dietary iron intake based on the China and US food composition databases. METHODS Total 368 records of 24-h dietary recall on mid-term pregnant women and lactating rural women were analyzed for their iron intakes with the China Food Composition Table 2002 and the USDA National Nutrient Database for Standard Reference release 25, respectively. The values of dietary iron intake derived from two composition databases were compared statistically. RESULTS The dietary iron intakes of total 368 dietary records estimated with China and US databases were (24.37 +/- 9.66) mg and (16.20 +/- 9.13) mg respectively (with paired t test, t = 20.081, P < 0.01, correlation coefficient r = 0.657, P < 0.01), with average ratio of 1.69 +/- 0.55 between China and US values. In terms of food classification, the most significant differences were with dairy products, fishes, fruits, meats and cereals, with ratios of (10.66 +/- 2.24), (5.10 +/- 5.51), (3.01 +/- 2.26), (3.01 +/- 7.85) and (2.33 +/- 0.77), respectively. Only iron intake values from tuberous crops and soy products had inverse ratio as (0.83 +/- 0.50) and (0.75 +/- 0.53). CONCLUSIONS The averaged dietary iron intake value for total records was very close to the reported national levels when estimated with the China Food Composition Table 2002, but much decreased when estimated with US food composition database with values as only approximately 66% of reported levels.