In this study, we examined the efficacy and toxicity of S-1 with cisplatin as a second-line palliative chemotherapy for gemcitabine-refractory pancreatic cancer patients. Patients who had been previously treated with gemcitabine-based chemotherapy as palliative first-line chemotherapy received S-1/cisplatin [body surface area (BSA) <1.25 m(2), S-1 40 mg/day; BSA ≤1.25 to <1.5 m(2), 50 mg/day; BSA ≥1.5 m(2) 60 mg/day, orally, bid, daily on days 1-14 followed by a 7-day washout and cisplatin 60 mg/m(2)/day intravenously on day 1] every three weeks. The enrollment of 32 patients was planned, but the study was terminated early, prior to the first stage, following the enrollment of 11 patients. The median age of the patients was 56 (range, 42-74) years. Nine patients had a performance status (PS) of one. In total, there were 21 chemotherapy cycles and the median treatment duration was 21 (range, 7-96) days. Of the 11 patients, five could not be evaluated due to discontinuation prior to the response evaluation. One of the six evaluable patients achieved stable disease (9.1% in intention to treat analysis and 16.7% in per-protocol analysis), while five had progressive disease. Grade 3-4 hematological toxicities were anemia in one, neutropenia in one and thrombocytopenia in one cycle. Grade 3-4 nonhematological toxicities were fatigue in three, nausea in four, anorexia in two, diarrhea in one and peripheral neuropathy in two cycles. With a median follow-up period of 8.9 (range, 3.2-11.3) months, the median time to progression was 44 days [95% confidence interval (CI) 25.4-62.6] and the median overall survival was 81 days (95% CI 9.3-152.7). Combination chemotherapy with S-1 and cisplatin as applied in this study did not result in promising antitumor activity, a high degree of toxicity and poor compliance.