Prostae cancer is the second leading cause of men’s cancer mortality. its management becomes a public health issue because of population’s aging. This support depends on several factors including Gleason score which the correlation between biopsy and prostatectomy specimen is not always guaranteed. Our retrospective study included 47 patients treated for prostate cancer with radical prostatectomy between March 2002 and January 2015. Data collection has been taken from the archives of Urologic Department of Military Hospital Moulay Ismail Meknes, has allowed comparing Gleason scores of needle biopsy to those of radical prostatectomy specimens. Other parameters were evaluated as age, PSA and correlation between differentiation groups (well, moderately and poorly differentiated). In our study, biopsy Gleason score had an overall accuracy of 70%, sub-staging of 25%, on-staging of 4.25% and a Kappa coefficient of 0.36 with best concordance observed in the moderately differentiated group. This study demonstrated, as in literature, that the biopsy Gleason score imperfectly reflects the one of radical prostatectomy specimens. The increase or decrease of the Gleason score shows the lack of precision in this classification system hence the need of improving the technical staging of prostate tumors on biopsy