Malignant peripheral nerve sheath tumors (MPNST) are rare. Although they originate from Schwann cells or pluripotent neural crest cells, they constitute less than 10% of all soft tissue sarcomas and more than 60% develop on the basis of neurofibromatosis. It is difficult to diagnose MPNST. Although it mostly occurs in the head and neck region or upper extremities, only 1% of cases are located in the retroperitoneal region. The main treatment is surgery, but survival results are not satisfactory even after surgery with R0 resection. They are not sensitive to chemotherapy and radiotherapy and tend to recur locally. The mass detected by imaging in a 57-year-old male patient who admitted to hospital with the complaint of abdominal pain was excised with clear surgical margins. The tumor was located in the left upper quadrant of the abdomen and seemed to invade the pancreas and left kidney in the computed tomography images. The patient had no history of neurofibromatosis or radiation. In this study, it was aimed to present our case diagnosed with retroperitoneal MPNST and treated with multiorgan resection, which is a rare entity, and to increase the awareness of clinicians about the diagnosis, treatment and prognosis of this rare tumor.