Accurate preoperative staging is important for adequate selection of patients for radical prostatectomy. We reviewed the preoperative PSA levels of 214 patients who underwent radical retropubic prostatectomy and analysed the results in relation to pathological stage. 32 (15%) patients had a PSA level below 4 ng/ml; nevertheless 8 of them had already a extracapsular disease and one present with positive lymph nodes. Thus, although a specificity of 90%, the sensitivity is only 18%. 98 (46%) patients had PSA levels beyond 10 ng/ml of which 47 (48%) had extracapsular tumor; this gives a specificity of 62% and a sensitivity of 59%. Finally 35 (16%) patients had a PSA over 20 ng/ml of which 18 (51%) present a extracapsular disease thus the specificity is 87% but the sensibility remains low at 23%. We concluded that although PSA levels are grossly related to the pathological stage, that relation is not reliable to distinguish patients with organ-confined from those who have extracapsular tumor extension and for either definition of a positive PSA level many patients would be denied a curative operation. Therefore, PSA value cannot be used to decide whether to recommend radical prostatectomy for potential cure.