The therapy of soft tissue sarcomas is not uniform. The goal of treatment for soft tissue sarcomas is surgical resection with negative microscopic margins. Other therapy options are pre-, intra-, or postoperative radiotherapy as well as neoadjuvantor adjuvant chemotherapy with different drugs, systemic or under local perfusion of the limb. If a margin-free surgical resection is not possible, intraoperative radiation therapy (IORT) offers the possibility for treatment of sites at high risk for local recurrence. The goal of this collaborating study of the Orthopedic University Hospital of Heidelberg and the department of Radio-Oncology of the University Hospital of Heidelberg is to observe the influence of IORT on the rate of local recurrence, complications, metastases, and survival in another wise unchanged tumor management. From 1960 to 1998,78 patients were treated for soft tissue sarcomas; 26 of 78 patients underwent intraoperative radiation and 52 patients were treated without intraoperative radiation. We found a recurrence rate of 15% in the IORT group and 29% in the non-IORT group. No difference for survival or distant recurrence was found, also no difference in early postoperative complication rate, but a higher rate of late complications after IORT (34% vs 7%) was remarkable. We think intraoperative radiation allows better local control and for that reason IORT is integrated into our therapeutic concept. Its influence on survival and distant metastases needs further investigations.