This study was carried out to determine whether a short-term zinc supplementation could improve the zinc status without adverse changes in copper status among type 2 diabetic patients. Seventy-six diabetic subjects and 72 normal adults participated in this study. Subjects were randomly divided into supplemented and control groups. Forty-four diabetic patients and 34 normal subjects were supplemented with 50 mg zinc gluconate daily for 4 weeks. Dietary intakes of participants were measured for two non-consecutive days by 24-hour recall method. Nutritional status of zinc and copper were also evaluated by biochemical measurement of fasting plasma samples and spot urinary collection. At baseline, diabetic patients showed significantly lower levels of dietary zinc intake and higher urinary zinc excretion than the normal adult group(p<0.05, p<0.0001). Plasma level of zinc was not significantly different between diabetic and normal adults at baseline. However, plasma zinc level increased significantly in both diabetic patients and normal adults after zinc supplementation. The changes in plasma copper levels following zinc supplementation were not statistically significant in diabetic subjects as well as in normal adults. These results indicated that four weeks of zinc supplementation did not influence Cu status and that it may contribute to improving the zinc status. Therefore, we suggest that Zn supplementation for a short-term period may improve marginal zinc status of diabetic patients without interfering with their copper status