The EORTC Soft Tissue Sarcoma Group was founded 25 years ago and has since developed into one of the leading cooperative groups in the research of sarcomas and has members from 40 institutions from 13 countries. The activities of the group have primarily been within the areas of standards for local as well as systemic treatment strategies, new drug development and quality control procedures. The group has a extensive quality control programme involving a strict membership policy, central review of the responses, central review of pathology, use a systemic therapy check-list and on-site monitoring of studies. A large database with over 2500 patients included in EORTC STBSG chemotherapy trials has been developed. So far, the STBSG has conducted more than 40 clinical trials accruing more than 250 patients per year, some of which has been performed in collaboration with other prestigious groups.