Résumé : The authors extracted 11 case files of patients undergoing radical prostatectomy following MRI studies from a series of 192 MRI examinations of the prostate with histological confirmation of the diagnosis. This series is part of a prospective study in which MRI was always interpreted prior to histological results. The diagnosis of prostatic cancer was confirmed in 9 cases on the basis of a hyposignal on T2-weighted scans. In 4 cases, extracapsular spread of the tumour was demonstrated by MRI and was confirmed at surgery. In the cases in which the cancer was visible on MRI, the diagnosis of local spread proved to be accurate. The debate concerning the role of MRI in prostatic disease is not definitively resolved, but this preliminary series indicates the potential and the limitations of this technique.