Non-organ retroperitoneal liposarcoma is the most frequent initial malignant tumor in retroperitoneal space and it comprises 40 % of all non-organ retroperitoneal tumors. Difficulty of early diagnostics and complex antitumor treatment of patients with non-organ retroperitoneal tumors is one of the most actual and complicated issues in oncosurgery. Nonorgan retroperitoneal liposarcoma is a problematic issue because of complicated topographic and anatomic position, adjacency to retroperitoneal organs and great vessels and frequent loco-regional recurring. The most effective treatment mode of non-organ retroperitoneal tumors is surgical. Traumatic multivisceral resections are needed in 50 % of observations, including nephrectomy in 35-39 % of cases. Morphological invasion of the tumor into organs is confirmed in 35.7 % of cases. According to the most observations (70 %), there are no signs of invasion into kidney. Today, the treatment of tumors is being reconsidered. Nowadays, the enhancement of professional knowledge and technological advancement provides an opportunity to implement kidney-preserving surgeries, which improve life quality of the patients. In our opinion, using renal autotransplantation is very promising. It is widely used in pathology, in non-urgent and urgent urology, oncourology, vascular surgery. Our clinical case has demonstrated the technique of extracorporal resection of giant liposarcoma from involved kidney. Further steps include temporary kidney conservation, precise dissection from tumor and replantation of iliac vessel under emergency morphological control. Follow-up period is 18 months. According to the instrumental examination, no indices of backset and of tumor growth were revealed and the kidney's integrity was saved.