Pelvic lipomatosis is a rare, relatively self-limiting disease characterized by the overgrowth of unencapsulated lipomatous tissue within the pelvis. The diagnosis is suggested, but not substantiated, by the striking roentgenographic changes noted on barium enema and intravenous pyelogram. Previously, pelvic laparotomy with tissue diagnosis was essential for documenting the disease. We report three cases in which computerized tomography was utilized as a safe, noninvasive and accurate method of diagnosis. The role played by partial venous obstruction is discussed in addition to rectal bleeding as a mode of presentation.