Background Although the docetaxel, 5-fluorouracil, and cisplatin triplet has yielded significant improvements in time to progression, overall survival, and overall response rate, the high incidence of severe adverse events limits the use of the docetaxel, 5-fluorouracil, and cisplatin triplet. To overcome this limitation, we evaluated the efficacy and safety of the combination of docetaxel, oxaliplatin, and S-1 for the treatment of metastatic gastric cancer. Methods Chemotherapy-naive patients with pathologically proven unresectable recurrent or metastatic gastric adenocarcinoma were assessed for eligibility. Docetaxel at 52.5 mg/m 2 and oxaliplatin at 105 mg/m 2 were administered intravenously on day 1, and S-1 was administered orally at 80 mg/m 2 on days 1-14 of every 21-day cycle.Results Forty-four patients (median age 54.5 years) were enrolled. All patients had metastatic disease. A total of 340 cycles of chemotherapy were administered (median of eight cycles per patient; range 1-36 cycles). Toxicities were evaluated in 43 patients, and the responses were evaluated in 40 patients. Major toxicities included grade 3/4 neutropenia (37.2 %) and leukopenia (27.9 %). The overall response rate was 54.5 % [95 % confidence interval (CI) 40.1-68.3 %] in the intention-to-treat population. The median progression-free survival and overall survival were 7.6 months (95 % CI 6.2-9.0 months) and 12.0 months (95 % CI 6.9-17.2 months), respectively. Conclusion These data suggest that the docetaxel, oxaliplatin, and S-1 combination regimen is effective and relatively well tolerable, and it seems to have potential to be a reasonable therapeutic strategy in patients with metastatic or recurrent gastric cancer.