Ifosfamide, an analogue of cyclophosphamide, has therapeutic activity against a wide variety of human malignancies. In a phase II trial in carcinoma of the pancreas, we treated 31 patients who had not received prior chemotherapy with a median ifosfamide dose of 2 g/m2/d (range, 1.5 to 2 g/m2/d) administered intravenously (IV) over one hour for five consecutive days every 3 weeks. 2-mercaptoethane sulphonate (mesna), an acrolein antagonist with known uroendothelial protective properties, was administered IV at a dose of 400 mg/m2 over 15 minutes before the daily dose of ifosfamide and repeated every four hours for two additional doses. Among 30 evaluable patients, one patient achieved a complete remission (26+ months) and another patient had a partial remission (4 months). The median duration of survival of all patients from the start of ifosfamide therapy was only 3 months (range, 1 to 26+ months). Treatments were generally well tolerated. The most common toxic effects included granulocytopenia, nausea and vomiting, malaise, anorexia, and mild hematuria. Mesna offers an adequate protection against uroendothelial injury caused by ifosfamide. Despite the previously reported response rate of greater than 20% at the same or lower doses of ifosfamide in other studies, our data suggest that ifosfamide is only marginally active against cancer of the pancreas and appears to be of minimal value in the treatment of patients with this tumor.