Prostate Specific Antigen (PSA) appears to be useful in the early detection of prostate cancer when used in conjunction with digital rectal examination (DRE) and transrectal ultrasonography (TRUS). Recent studies suggest that the addition of PSA to the routine digital rectal examination leads to detection of prostate cancer at an earlier stage than when digital rectal examination is used alone. In patients with elevated PSA or abnormal DRE prostate biopsies are recommended. However, the routine use of PSA to detect early prostate cancer is limited due to the PSA elevation in patients with prostatic hyperplasia. Possibilities to distinguish BPH from prostate cancer among men who have minimal PSA elevation (4.0 to 10.0 ng/ml) are the use of PSA velocity, PSA density, age adjusted PSA, and analysis of free and complexed PSA. Screening programs for prostate cancer will increase the percentage of localized prostate cancer, which can be cured by radical prostatectomy.