We summarized and reviewed published reports, including our studies, on the reverse transcription-polymerase chain reaction (RT-PCR) detection of micrometastatic prostate cancer cells in lymph nodes, bone marrow and peripheral blood. Some published data preliminarily suggest that the RT-PCR assay of micrometastatic prostate cancer cells may allow a more accurate assessment of lymph node and bone metastases of prostate cancer, and offer a presurgical prediction of the pathological stage of clinically localized disease. In addition, the RT-PCR assay may have a unique prognostic value in prostate cancer. However, controversy remains over the clinical significance of the RT-PCR assay. This assay could potentially develop into a diagnostic procedure for the clinical decision making in patients with prostate cancer. To establish the clinical significance of the RT-PCR assay, further optimized and standardized RT-PCR assay studies are needed, investigating large populations and involving long-term follow-up for the determination of any association between the results of the RT-PCR assay and specific clinical outcome.