The authors retrospectively reviewed 140 MR examinations of the prostate to assess the presence of similar findings in the different patients affected with the same prostatic disease. In 35 patients with acute phlogosis, MR imaging showed enlargement of peripheral gland, with increased signal intensity on T2-weighted images, while reduced peripheral gland with low signal intensity was demonstrated in chronic phlogosis. Five patients presented roundish cystic lesions, with clear-cut outlines, clearly distinguishable from the surrounding parenchyma. Benign Prostatic Hyperplasia (BPH) was observed in 32 cases. 52% of them had multiple nodules with high signal intensity, 40% had hyperintense enlarged central glands, with no evidence of BPH nodules, and the remaining 8% presented single/multiple nodules with low signal intensity. In 56 patients with prostatic carcinoma the tumor extent ranged from 18-20 mm nodules to 5-6 cm masses with involvement of periprostatic adipose tissue or surrounding organs. The smallest lesions were always found in the peripheral gland and had low signal intensity on T2-weighted sequences. In spite of the different findings in the patients affected with BPH, the study proved MR imaging to be able to distinguish the various patterns of the different prostatic diseases.