Zinc is important for insulin synthesis, storage and secretion. When zinc concentration decrease, there is a concomitant reduction in insulin secretion and peripheral insulin sensitivity. To assess the effects of zinc sulfate on insulin sensitivity, leptin and androgens in obese individuals. A randomized, double-blind, placebo-controlled clinical trial was performed in 14 obese volunteers between 21 and 30 years old, with body mass index (BMI) (3) 27 kg/m2. During one month, seven subjects received 100 mg/day of zinc sulfate orally (ZnG) and the other seven received placebo, as control group (CG). At baseline and after the intervention, insulin sensitivity was measured using a euglycemic-hyperinsulinemic clamp technique. Blood glucose, serum lipids, zinc, androgens and leptin were also measured in a fasting blood sample. After the intervention, a rise in zinc concentrations from 11.8 to 16.9 umol/L; p=0.001 and in leptin levels from 15.2 to 27.7 ng/mL; p=0.029, was observed in the ZnG. No changes were observed in the CG. There were no significant changes in insulin sensitivity and androgens after the intervention with zinc sulfate. Zinc increased the leptin concentrations in obese individuals, but did not modify insulin sensitivity and androgens.