The aim of our study was to verify possible utilization of RT-PCR method (Reverse Transcriptase-Polymerase Chain Reaction) as a diagnostic and prognostic modality of the progression of prostate cancer. This approach is commonly used for the detection of circulating carcinomatous cells in peripheral blood of patients with malignant breast tumors, and our ambition was to adopt this method for patients with prostate cancer. The contribution of this method consists in its ability to detect early stages of the dispersion of carcinomatous cells, so called micrometastases, in the peripheral circulation of patients. The estimation of the progression of the disease is especially important for the selection of appropriate therapy for individual patients. Using this method we analyzed 50 men: 28 patients with clinically localized or locally advanced prostate cancer, 7 patients with clinically proven metastases, 8 patients with benign prostatic hyperplasia, and 7 healthy young men.