This study was conducted to evaluate the safety and efficacy of S-1 and paclitaxel combination therapy for patients with advanced gastric cancer. Eligible patients had previously untreated advanced or relapsed gastric cancer with measurable lesion(s) and an ECOG PS of 0-2. Treatment consisted of S-1 35 mg/m(2) p.o. b.i.d. on days 1-14 followed by a 7-day off plus paclitaxel 70 mg/m(2) i.v. on days 1 and 8 of a 21-day cycle. Fifty-six patients (M/F = 37/19) were enrolled. The median age was 59 years. The median number of cycles administered was six (range 1-18). Out of the 53 patients evaluated, there was 1 (1.9%) CR, 20 (37.7%) confirmed PRs, 5 (9.4%) unconfirmed PRs, 21 (39.6%) SDs, and 6 (11.3%) PDs. The objective tumor response was 39.6%. The median time to progression was 29 weeks. The median survival was 51 weeks. All 56 patients were assessed for treatment safety. The treatment was well tolerated with grade 3/4 neutropenia in 20%/13%, grade 3 febrile neutropenia in 7%, grade 2/3 diarrhea in 9%/4%, vomiting in 11%/0%, stomatitis in 4%/4%, and neuropathy in 4%/0% of patients. S-1 and paclitaxel combination treatment is an effective regimen with a favorable toxicity profile in patients with advanced gastric cancer.