Objective: To determine the relative validity of a newly developed iron intake assessment tool, designed specifically to assess iron, calcium and vitamin C intake. Design: Estimates of iron, calcium and vitamin C intake from a computerised iron intake assessment tool compared with those from 11-day estimated dietary records. Setting: Region of Ghent (N ¼ 7225 000), a city in Flanders, the Dutch-speaking part of Belgium. Subjects: In all, 50 women aged 18-39 y, participating in a large-scale epidemiological study on iron intake and iron status. Main results: Mean dietary iron intake from the 11-day food record, the unadjusted dietary iron intake assessment tool and the adjusted tool was, respectively, 10.572.7, 10.474.3 and 9.672.9 mg. For the different nutrients, the correlation coefficients vary from 0.45 to 0.60 for adjusted intake. The mean difference of iron intake by the two methods (0.872.9 mg) did not differ significantly from zero. The new method correctly classified 38% (iron), 38% (calcium) and 58% (vitamin C) of the subjects to the correct tertile. The correlation coefficients ranged from 0.48 for adjusted vitamin C intake to 0.73 for adjusted calcium intake between two administrations. Conclusion: The newly developed instrument can be used to assess mean group intakes of iron, calcium and vitamin C in women consuming a Western diet. However, since the ranking capability of the new tool is rather weak, further refinement of the tool is required to produce a robust method for assessing iron, calcium and vitamin C intakes of individuals.