Retroperitoneal liposarcoma (RPLS) is a rare malignancy with a high recurrence rate. Giant RPLS (≥30 cm) poses significant surgical challenges due to its invasive nature and compression of vital organs. Early diagnosis and multidisciplinary management are critical yet underreported in young patients. This case highlights the complexity of managing a 36-year-old male with a 60 cm × 50 cm × 40 cm tumor, emphasizing the importance of surgical precision and collaborative care.The patient is a 36-year-old male who was admitted to the hospital due to abdominal distension presenting for over 7 months, accompanied by a rapid increase in abdominal girth for over the past 2 months. Based on his symptoms, physical examination findings, and imaging studies, the possibility of a giant retroperitoneal liposarcoma was considered.Giant retroperitoneal liposarcoma.The treatment involved the resection of the massive retroperitoneal tumor, along with partial resection of the descending colon, left ureterostomy drainage, and release of intestinal adhesions.The patient was discharged 14 days postoperatively with no immediate complications. Albumin levels improved to 35.2 g/L at 1-month follow-up. Telephone follow-ups at 3, 6, 12 months, and 5 years revealed no signs of recurrence on abdominal ultrasound.The tumor had already invaded the surrounding organ tissues at the time of discovery in this case. Comprehensive preoperative evaluation, multidisciplinary collaboration in diagnosis and treatment, precise surgical techniques, and standardized intraoperative and postoperative management are essential to enhance surgical resection rates, minimize complications, and decrease the likelihood of postoperative recurrence.Copyright © 2025 the Author(s). Published by Wolters Kluwer Health, Inc.