The combination of gemcitabine with protracted 5-fluorouracil (5-FU) in the treatment of metastatic pancreatic cancer has shown activity with tolerable toxicity. The administration of UFT may simulate the effects of a protracted infusion of 5-FU. Patients with previously untreated metastatic or unresectable measurable pancreatic adenocarcinoma received gemcitabine (800 mg/m2 i.v., administered as an 80-min infusion on days 1, 8 and 15), UFT (200 mg/m2/day, on days 1 to 21), and oral leucovorin (90 mg/day, on days 1 to 21). Thirty patients were enrolled in this study. Five patients had partial responses, with an overall response rate of 17% (5/30), using the intent-to-treat principle (95% confidence interval (CI), 3-30%). Nine out of 25 (36%) patients experienced clinical benefit responses (95% CI; 17-55%). The median time to progression was 3.0 months, and the median overall survival was 7.2 months. The principal adverse event was neutropenia. The combination of gemcitabine, UFT, plus oral leucovorin shows significant antitumor activity and a beneficial clinical effect with an acceptable level of toxicity.