This preliminary analysis of surgical data is based on the evaluation of 323 patients operated on for soft-tissue sarcoma of varying histology. Data were collected for the Cooperative Soft-Tissue Sarcoma Study of the Gesellschaft für Pädiatrische Onkologie (Society of Paediatric Oncology). The following preliminary results are presented: 1. The number of mutilating operations, formerly undertaken with great frequency, can be reduced by chemotherapy, except where very aggressive tumours necessitate radical tumours excision. 2. According to the protocol in use, second look operations were performed in 117 patients, usually following the second course of chemotherapy. It is concluded that second look operations should be performed between the 16th and 19th post-operative week. Patients with scars in the former tumour bed must be assessed particularly critically, since residual tumour nodes may be masked by the scars.