A free screening clinic for cancer of the prostate was held in Madison County, New York, in September 1990, in conjunction with Prostate Cancer Awareness Week, a program of the Prostate Cancer Educational Council. Serum prostate specific antigen and digital rectal examination were used to screen 565 men. The two tests were equally effective in identifying patients with carcinoma. Of 118 patients with one or both tests positive, 54 were biopsied. Carcinoma was found in 20 of these. Four carcinomas were found in patients with prostate specific antigen (PSA) greater than four ng per ml with negative rectal examination. The costs for adding PSA to the protocol appeared reasonable in terms of the number of carcinomas identified.