The aim of this phase I/II study was to evaluate the tolerability and efficacy of combination chemotherapy with gemcitabine (GEM) and UFT for advanced pancreatic cancer. In phase I study UFT was given orally every day for 14 days and GEM was infused on day 1 and 8 at three dose levels (800, 900, 1,000 mg/m(2)/week) every 21 days. GEM 1,000 mg/m(2) and UFT 400 mg/m(2) did not reach the maximum tolerated dose. We decided that the recommended dose (RD) was GEM 1,000 mg/m(2)and UFT 400 mg/m(2). In phase II study 27 patients were enrolled and received GEM and UFT at RD. The tumor response rate was 17.6%, and the median survival was 221 days, which was very similar to that of GEM monotherapy. Due to adverse events, especially liver dysfunction, protocol therapy was discontinued in 12 patients. This study could not revealed the superiority of the GEM monotherapy.