The role of surgical resection remains controversial in malignant pleural mesothelioma. The assessment of its impact on prognosis is complicated by a poor understanding of the prognostic factors in the disease. We therefore evaluated, through univariate and multivariate analysis, the role on prognosis of 24 variables in 57 patients submitted to surgery from 1985 to 1993. Sixteen patients had only exploratory thoracotomy and 12 minimal residual disease after surgery (no nodules >1 cm in diameter). Thirty-four cases had epithelial histotype, 6 sarcomatous and 17 mixed. Median survival for the whole group was 15.7 months. Multivariate analysis showed a highly significant influence on survival for minimal residual disease after surgery (p=0.0006), followed by TNM stage (p=0.01). Median survival for patients with TNM stage I disease was 36.3 months and for patients with minimal residual disease 33 months. In conclusion, these data suggest that patients with limited disease have a longer survival after surgery than those with extensive disease. At the same time, our results indicate that the achievement of significant disease reduction with surgery has a critical impact on the prognosis of pleural mesothelioma.