Prostate cancer (PCa) is the second leading cause of death in men aged 40 years and older ]and prognostic indices are useful in suggesting its proper treatment. The aim of this study was to evaluate the prognostic value of Gleason score (GS), TNM staging system, initial serum prostate specific antigen (PSA) and bone scintigraphy (BS) in patients with PCa under hormonal palliative treatment, in the development and progression of recurrent PCa. Our methods were as follows: Between January 2005 and December 2007, we have studied at the University General Hospital of Alexandroupolis fourty patients of mean age 77+/-7.2 years with advanced PCa under palliative treatment with antiandrogens and luteinizing hormone-releasing hormone analogues. PCa was diagnosed histologically, based on the TNM system after transrectal ultrasonography guided biopsy. The Gleason score assessment was made as described by others. Metastases were confirmed by a positive bone scintigraphy with 925 MBq (99m)Tc-MDP using a tomographic gamma camera, computerized axial tomography or magnetic resonance imagining. Measurements of PSA were conducted by the radioimmunoassay method. We also examined 20 healthy blood donors (median age 45+/-6.1 years) as controls, in order to estimate the cut-off value of PSA. Our results show the following: Thirteen of our patients had 1-6 "hot" spots and 27 had more than 6 "hot" spots in the bone scan. The median Gleason score was 7 (modal Gleason score 3+4). Serum PSA levels were higher in patients with PCa and bone metastases in comparison to those with PCa without bone metastases. Very high values of PSA (more than 50 ng/ml) were found in patients with multiple bone metastases (>6 "hot" spots). In conclusion, our findings demonstrate that the prognostic value of GS (P=0.043), TNM staging (P=0.1410), serum PSA levels (P=0.002) and BS (P=0.0135) when used alone, not always improve the prognosis to hormone indepentent but when combined (P<0.001) increase the prognosis in patients with advanced PCa under hormonal palliative treatment.