Iron (Fe), copper (Cu) and zinc (Zn) deficiency coexist in developing countries. Supplementation and fortification programs with combined micronutrients have been implemented, but possible negative interactions of these minerals absorption should be considered. The aim of this study was to evaluate the effect of a daily supplementation with 30 mg of Fe alone or in combination with 30 mg of Zn on Cu status in Chilean women of childbearing age. This was a randomized, double-blind, placebo-controlled trial, in which 81 women aged 18 - 45y were randomly assigned to receive either a daily single dose of 30mg of Fe or this mineral combined with 30mg of Zn or placebo. The concentration of serum copper (CuS), ceruloplasmin (Cp mass) ceruloplasmin activity (Cp activity) and specific activity (Cp activity/Cp mass) were evaluated at baseline and at the end of the study. The daily combined Fe and Zn supplementation significantly decreased CuS concentration (2-way ANOVA for repeated measures p<0,01), but Fe alone did not affect Cu status. Fe with Zn supplementation did not affect Cp mass, Cp activity and specific activity. In conclusion, combined supplementation of Fe and Zn in doses of 30mg each, significantly decreases CuS concentration.