A retrospective analysis was done on 135 consecutive patients with extremity and truncal synovial sarcomas seen at our institutions between 1961 and 1996. Ninety-nine patients (73%) presented with a newly diagnosed localized primary sarcoma, nine patients (7%) presented with a locally recurrent sarcoma previously treated at another institution, and 27 patients (20%) presented with metastatic disease. The median followup for surviving patients was 78 months (range, 20-420 months). The overall survival for patients with localized primary and locally recurrent synovial sarcoma was 51% at 10 years. Patients with localized synovial sarcomas less than 5 cm in longest diameter had a survival at 10 years of 88% compared with a 10-year survival of 38% and 8% for patients with sarcomas 5 to 10 cm and greater than 10 cm in longest diameter, respectively. Distal location (hands and feet) and histologic grade also were statistically significant predictors of patient survival for localized synovial sarcoma on univariate analysis. On multivariate analysis size greater than 10 cm and size 5 to 10 cm were associated with an 18-fold and a 3.1-fold increased risk of death compared with tumors smaller than 5 cm. Grade and location were not found to be independent predictors of survival on multivariate analysis. Primary tumor size and initial status at presentation were prognostic for survival and patients with synovial sarcomas larger than 5 cm or locally recurrent at presentation should be considered for more aggressive surgical and adjunctive radiotherapy or chemotherapy.