The article is a discussion of three cases of lipomatosis in the pelvis and of the surgical treatment undertaken in each case. In the first two cases, fatty tissue compressed the lower uriunary tract, and in the third, the rectosigmoid intestine. In the third case, the patient was also diagnosed as having a malignant rectum polyp. In all three cases, the diagnosis by ultrasound, intravenous urography and rectoscopy was confirmed by CT. All three patients underwent surgery. The first patient was erroneously surgicaly treated in another clinic. The operation involved resection of the terminal part of ureters and, on the antireflux principle, the reimplantation of ureters into the bladder. The patient's condition seriously deteriorated in a short time. In the second case, we removed some fatty tissue from the patient's pelvis and performed ureteroileocutaneostomy. At present, 14 years since the operation, the patient's condition is good. The third patient had malignant rectum polyp, so we removed a large part of fatty tissue and performed resection of the anorectum and the distal part of the sigmoid colon, together with "anus praeter naturalis unipolaris sigmoidalis". The patient's condition, 10 years since the operation, is good.