In this study, 1,027 healthy men over age 40 were screened for prostate cancer with digital rectal examinations (DRE) and prostate-specific antigen (PSA) levels. Findings were abnormal in 189 (18%). PSA levels alone were abnormal (> 4.0 ng/mL) in 111 men (12%), 60 men (8%) had abnormal DRE and normal PSA, and 18 men had abnormal results of both examinations. Of the 189 men, 176 (93%) were referred for follow-up studies, and 39 cases of prostate cancer were detected. Of the 60 men with abnormal findings on DRE and normal PSA levels, only 2 men (3%) were found to have prostate cancer. Twenty-two of the 107 men (21%) with PSA levels between 4.0 and 9.9 ng/mL and 14 of 22 men (64%) with a PSA level greater than 10 ng/mL had prostate cancer. Conversely, 36 of the 39 men (92%) with prostate cancer had a PSA level greater than 4.0 ng/mL. Of 18 men with both abnormal DRE and elevated PSA, 9 (50%) were found to have prostate cancer. Overall, the 39 men found to have prostate cancer constituted 3.8% of the population screened; 25 of them (64%) had disease clinically confined to the prostate. PSA in combination with DRE appears to be useful in detecting prostate cancer in its early stages. Prospective randomized trials must be completed to determine whether early detection will have an impact on overall mortality from prostate cancer.