Current urologic literatures were evaluated to summarize current status of serum prostate specific antigen (PSA) in the early diagnosis of prostate cancer. Serum PSA is now a routine part of the investigation of men with suspected prostate cancer. While it still has its problems, in particular its lack of specificity, it is a very useful test. Since PSA may overlap in men with and without prostate cancer, other derivatives of PSA were developed to enhance the ability for detecting early stage prostate cancer. This review describes the current status and problems with PSA testing in prostate cancer diagnosis and highlights potential ways in which these may be reduced.