Malignant pleural mesothelioma represents a rare disease, for which chemotherapy actually remains unsatisfactory. From August 1998 to November 2001, 28 chemo-radio-immunonaive patients were consecutively enrolled in the trial: 22/6 males/females; median age 63 years (range, 45-79); median ECOG PS 1 (range, 0-2). They were treated with epirubicin (100 mg/m2 iv on day 1) plus gemcitabine (1000 mg/m2 iv on days 1 and 8) every 4 weeks for 6 cycles. Patients who responded to chemotherapy (n = 6) were subsequently treated with interleukin-2 (4,500,000 IU) subcutaneously every other day, until progression. A total of 124 epirubicin-gemcitabine cycles were administered (median, 6/patient; range, 2-6). Twenty-six patients were evaluated for toxicity. According to WHO criteria, we observed grade III-IV hematological and gastrointestinal toxicity respectively in 3 patients (11%) and 1 patient (3%). No red cell transfusions were required and no toxic deaths occurred. Two patients (8%) could not be evaluated for response (no therapy performed). According to WHO criteria, the final responses were: partial in 4 patients (14%), stable disease in 19 patients (69%), and progression in 3 patients (10%). In 26 patients, the median survival was 55 weeks (range, 7-222) and median time to progression 30 weeks (range, 4-156). At the time of this writing, no patient is alive. The 1-year survival was 32%, 2-year survival 11%, and 4% at 3 and 4 years. All patients were at stage III, and time to progression was 58 weeks and survival 63.5 weeks, without any toxicity. This multi-center phase II clinical trial showed that epirubicin plus gemcitabine, as a first-line treatment in malignant pleural mesothelioma, has promising activity with a good tolerability profile and symptom palliation. The role of interleukin-2 in maintenance therapy for malignant pleural mesothelioma is encouraging and requires further study.