The differential diagnosis of masses in the perinephric space and the peripelvic space of the renal hilum would include tumor, fluid, inflammation, or various proliferative diseases. More broadly, abnormal tissue at the periphery of the kidney may be subcapsular or perinephric in origin, and these processes are not always distinguishable. Radiologic evaluation of renal and perinephric masses is gaining an increasing importance. We report one such case of a right perinephric mass which posed a diagnostic dilemma.