Retroperitoneal sarcomas are rare tumors that develop in the mesenchymal tissue, where liposarcoma is the most frequently encountered subtype. The symptoms they induce are often vague and nonspecific, thus requiring thorough evaluation. Their diagnosis primarily relies on imaging techniques such as CT scans and MRI, and is confirmed by biopsy. Despite excision surgery, which remains the main treatment aiming for total resection, local recurrences remain a frequent challenge. Although radiotherapy and chemotherapy in the perioperative period are sometimes considered, their effectiveness remains subject to debate. The histological type of the tumor is of paramount importance in prognosis, with well-differentiated liposarcomas being associated with better outcomes than myxoid or dedifferentiated forms. Optimal management of these tumors requires a multidisciplinary approach, involving close collaboration between surgeons, oncologists, radiologists, and pathologists to ensure adequate and personalized treatment. Hence, the interest of a case of giant retroperitoneal liposarcoma in a 65-year-old man that we managed and report here.