From 1965 to 1985, 262 patients with malignant pleural mesothelioma were treated with cytostatics only; radiotherapy (RT); RT and cytostatics; or decortication plus RT plus cytostatics. The median survival (MS) from diagnosis was 9.6 months. This was similar for all comparable treatment groups. In a univariate analysis, significant favorable prognostic factors were good performance status (PS), duration of symptoms greater than 6 months at the time of diagnosis, early stage of disease, white race, and female sex. In a multivariate analysis, PS, race, duration of symptoms, and stage were of significance for a favorable prognosis. Age, pain as first symptom, histologic subtype, and RT dose were not of prognosis significance in this study. The stepwise addition of treatment modalities did not increase survival, which remained the same as that reported for untreated patients. Therefore, phase II trials of new agents offer the only hope for advance in the treatment of this disease.