The aim of this work was to evaluate the usefulness of MR imaging in the diagnostic study of seminal vesicles and to emphasize the relationships between this technique, CT scan and trans-rectal ultrasonography (TR-US). We discussed pathological findings due to congenital anomalies, phlogistic or neoplastic lesions and iatrogenic changes of normal tissues. MR imaging and TR-US seem to be the most reliable techniques for typing pathological tissues and for grading the extension of neoplatic masses arising from bladder, prostate, and rectum, involving seminal vesicles.