We conducted a phase II multicenter trial to evaluate the activity of combined gemcitabine and oxaliplatin in malignant pleural mesothelioma. Twenty-five patients were recruited between May 1999 and December 2001 and received gemcitabine 1000 mg/m2 intravenously over 30 minutes and oxaliplatin 80 mg/m2 intravenously over 3 hours on days 1 and 8 of a 21-day cycle for a maximum of 6 cycles. Eligibility criteria included an Eastern Cooperative Oncology Group performance status of 0-2 and no prior chemotherapy. Best objective responses achieved were as follows: partial response, 10 patients (40%, 95% CI, 21%-61%); stable disease, 6 patients (24%, 95% CI, 9%-45%); and progressive disease, 9 patients (36%, 95% CI, 18%-57%). Median time to disease progression was 7 months, and median survival was 13 months. One-year survival was 60% (95% CI, 31%-72%). There were 2 deaths from disease progression. Toxicity was mainly hematologic. Grade 3/4 nausea and vomiting occurred in 8% of patients, neuropathy occurred in 8% of patients, and diarrhea occurred in 4% of patients. The combination of gemcitabine and oxaliplatin was shown to be active in malignant pleural mesothelioma and to exhibit tolerable toxicity in an outpatient setting.