Retroperitoneal sarcomas comprise approximately 15% of all soft tissue sarcomas and 50% of all retroperitoneal tumours. Helical CT of the abdomen and pelvis, with selective use of MRI will establish the extent of the tumour, its retroperitoneal location, the degree of necrosis, and the evidence of metastasis. A CT guided core needle biopsy is the optimal pre operative tissue sampling. A complete surgical resection is the mainstay of the treatment with a rim of normal tissue that often requires removal of adjacent organs. The 5-year probability of local control is approximately 50%. The role of adjuvant therapy is evolving and at present should not be used outside the investigational setting.