Aim/Objective: Retroperitoneal soft tissue sarcoma; epidemiological, histopathological features of cases in our clinic, treatments and their clinical courses were compared with the literature. Materials and Methods: Records of 7 patients who were operated in Surgical Oncology Clinics of Süleyman Demirel University between 2007-2013 after being detected with primary retroperitoneal- intraperitoneal masses in imagings and being reported as soft tissue tumor in histopathological examination were analyzed retrospectively. Results: The patients were 6 males and 1 female. Abdominal tomography was applied to all patients and in imagings there were both intraperitoneal and retroperitoneal masses in 4 patients (57,1%), left retroperitoneal masses in 2 patients (28,6%) and intraperitoneal mass in 1 patient (14,3%). Distant metastases weren’t detected in any of the patients at the time of diagnosis. While mass excision was done in 2 patients, enbloc organs resection (colon and kidney) was done along with excision in 3 patients, two patients were admitted as unresectable. In pathological examination, 42,9% (in 3 patient) good differential liposarcoma, 28,6% (in 2 patient) leiomyosarcoma and 14.3% (1 patient) dedifferentiated liposarcoma and rhabdomyosarcoma were detected. Recurrence developed in 2 patients who were applied mass excision in 11th month (10th month and 12th month) on the average. Lung metastases developed in one patient in the 6th month who were applied enbloc organ and mass resection. Conclusion: Retroperitoneal soft tissue sarcomas are rarely seen. However, recurrence often develops generally due to incomplete surgery. Therefore, aggressive surgery is recommended in these tumors in order to provide negative surgery border