The prognosis in prostate cancer depends on several clinical-morphological factors, such as Gleason score, pTNM and preoperative PSA level. Reliable biological markers are being sought to supplement clinicalmorphological data in order to better predict prognosis and to select an individualized therapeutic option. The aim of this study was a comparative analysis of the expression of biological markers, such as Hif-1<i>&#945;</i>, bcl-2, p53, Ki-67, cyclin D1 and CD44 in BPH and prostate cancer, as well as examining their association with standard prognostic factors in prostate cancer. The immunohistochemical analysis was made on 82 formalin-fixed, paraffin- embedded tissue blocks: 43 prostate cancer specimens derived from patients who had undergone radical resection, and 39 prostate bioptates derived from patients with BPH. A positive correlation was demonstrated between Gleason score and the expression of both Hif-1<i>&#945;</i> (R = 0.32, p < 0.05) and Ki-67 (R = 0.30, p < 0.05). Additionally, a negative correlation was demonstrated between tumor stage (pTNM) and bcl-2 expression (R = &#8211;0.35, p < 0.05). Hif-1<i>&#945;</i> as a hypoxia marker and Ki-67 as a proliferation marker, both correlated with Gleason score, may constitute important additional prognostic indicators in prostate cancer patients. (<i>Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 452&#8211;457</i>)