Mesothelioma is a rare disease for which neither single modality nor bimodality therapy improves survival. For this reason, from 1980 to 1995, we used trimodality therapy in an attempt to improve survival in selected patients at Brigham and Women's Hospital and Dana-Farber Cancer Institute. One hundred twenty patients underwent trimodality treatment involving extrapleural pneumonectomy followed by combination chemoradiotherapy. Twenty-seven women and 93 men (mean age, 56 years) were evaluable for response and treatment-related morbidity. The operative mortality rate was 5%, and 22% of patients experienced major morbidity. Cell type and nodal status were significant prognostic variables. The respective 2- and 5-year survival rates were 45% and 22% overall, 70% and 37% for patients with epithelial cell type, 20% and 0% for patients with sarcomatous or mixed-histologic-type tumors, and 74% and 39% for patients who were nodenegative with epithelial histologic type. Positive resection margins impacted survival only in the case of full-thickness, transdiaphragmatic invasion. A revised staging system stratified survival with median intervals of 22, 17, and 11 months for stages I, II, and III disease, respectively (p=0.04). Thus, extrapleural pneumonectomy with adjuvant therapy is appropriate and effective treatment for patients with stage I disease according to the revised staging system.