Zinc concentration in a prostate gland is much higher than in other human tissues. Data for zinc changes in different prostate diseases are limited and greatly contradictory. To analyze transrectal puncture tissue biopsy and resected materials, zinc content was estimated in benign prostatic hyperplasia (BPH) and cancer. There were 109 patients studied (50 BPH and 59 cancer). The control group consisted of 37 intact glands of men who died an unexpected death (accident, murder, acute cardiac insufficiency, etc.). All materials studied were divided into two parts. One of them was morphologically examined, while the zinc content of another one was estimated. The radionuclide induced energy dispersive X-ray fluorescent analysis was used for zinc determination. Zinc content (M +/- SE) of normal prostate, BPH and cancer was 1018 +/- 124, 1142 +/- 77, and 146 +/- 10 micrograms/g dry tissue, respectively. It was shown that zinc assessment in the material of transrectal puncture biopsy of prostate indurated site can be used as an additional test for differential diagnosis of BPH and cancer. Accuracy, sensitivity and specificity of the test are 98 +/- 2%.