We studied copper (Cu) and some other trace element (Fe, Mg, Zn, and Ca) levels which continuously interact with Cu in hair, nail, serum, and urine of copper intrauterine device (IUD) wearers. This study was performed on 3 groups of women. Twenty-two healthy women were studied as control group (group II), the second group included 18 healthy women who had been using IUD for more than 2 years (group III), and third group included 23 healthy women who had been using IUD for less than 2 years (group III). Cu levels in hair were 37.9 +/- 16.3 ppm in control group, 49.3 +/- 20.0 ppm (p < 0.025) in group I, and 64.5 +/- 29.2 ppm (p < 0.0005) in group III. Cu levels in nail were 21.9 +/- 5.35 ppm in control group, 25.96 +/- 9.05 ppm (p < 0.05) in group II, and 37.71 +/- 11.3 ppm (p < 0.0005) in group III. There was a statistically significant difference between group II and III (p < 0.005). Cu levels were 2.51 +/- 1.1 mu g/ml and 0.33 mu g/ml in serum and urine, respectively in control group, and there were no significant differences between the ether groups. Important differences were also found in the levels of the other trace elements among the groups. In the intracorrelation analyses, positive and negative correlations were present among hair, nail, serum, and urine Cu and the other trace element levels of women using IUD. High levels of Cu in hair and nails showed that Cu, which is released from IUD to intrauterine cavity, was absorbed into the bloodstream and deposited into several organs and tissues like hair and nail. However, requirement of quantitative estimation of excess copper accumulation in tissues by periodical analyses of hair and nail samples from the subjects is controversial.