In an attempt to detect prostate cancer when the disease was still localized, a free screening clinic was established for men over the age of 45 years. Digital rectal examinations were performed for 811 men. Prostate biopsy was recommended to 43 in whom abnormalities were found by digital rectal examination; only 38 complied. Prostate cancer was detected in 11 men. The patients with cancer ranged in age from 60 to 79 years, with the highest incidence of cancer in the group aged 70 to 79 years. The overall incidence in men between 51 and 80 years old was 1.7%. Staging evaluation revealed that none of the patients with prostate cancer had metastases to the bone or elevated serum acid phosphatase levels. Five men (45%) were found by clinical or pathological methods to have stage B disease. Two others (18%) showed radiographic evidence of lymph node metastases (stage D1). The cost of detecting each cancerous prostate tumor was approximately +6,300. Routine screening can be a cost-effective method for diagnosing prostate cancer in patients with less extensive disease. The ability of early detection to prolong survival of patients with this disease will require further investigation.