Changes in serum nickel, copper and zinc were evaluated in 45 Norplant users. Two groups were selected for this study. Group I included 15 regularly menstruating females as controls and as short-term users (90 days after Norplant insertion). Group II included 30 Norplant users for one year or more as long-term users. These elements were determined by atomic absorption spectrophotometry. Serum nickel showed no significant change in short-term nor in long-term users when compared to the control group or to each other. Serum copper and zinc revealed a significant increase in short-term users for a short period of time, which returned to normal levels in long-term users. There was disappearance of the cyclic changes in serum copper and zinc concentrations on comparing their levels in ovulatory to non-ovulatory Norplant users. The use of Norplant has no deleterious effects on serum levels of nickel, copper and zinc.