Serum copper and zinc concentrations were determined in 46 leprosy and 85 pleural tuberculosis patients and compared with those of 77 healthy subjects. Diagnosis was performed by clinical and laboratory findings. Serum copper and zinc concentrations were determined by colorimetric methods. Variance analysis and correlation analysis tests were used for statistical evaluation. Serum copper concentrations in leprosy patients were found as 135.61± 24.67 µg/dl, in patients with tuberculosis 167.28±37.54 µg/dl and, in healthy subjects 113.94±20.39 µg/dl Serum zinc concentration in leprosy patients were determined as 108.70±27 .92 µg/dl, in patients with tuberculosis 99.62 ±21.48 µg/dl, and in healthy subjects 117.30 ±21.42 µg/dl The increase in copper and decrease in zinc levels of serum may be attributed to the acute phase reactions of the host against infectious or noninfectious inflammations. Leprosy and tuberculosis have got similar characteristics related to their etiology, immunology and cytopathological aspects. The determination of serum copper and zinc concentrations may provide a new approach for evaluation of the immune status of leprosy and tuberculosis.