Background: Even among completely resected gastric cancer patients treated with adjuvant chemotherapy, stage III patients show bad prognosis and somewhat better treatment option is needed. Docetaxel or cisplatin each added to S1 monotherapy showed survival benefits in advanced gastric cancer. Methods: We conducted randomized, multicenter, phase III trial to compare S-1 plus docetaxel (DS) with S1 plus cisplatin (SP) in stage III gastric cancer patients. Gastric cancer patients (AJCC 7^th stage III) who had had curative D2 gastrectomy were randomized 1:1 to receive adjuvant chemotherapy of eight 3 week cycles of DS (S-1 70mg/m²/day on day 1-14 plus docetaxel 35mg/m² on day 1, and day 8) or SP (S-1 70mg/m²/day on day 1-14 plus cisplatin 60mg/m²on day 1). The primary endpoint was 3-year disease-free survival (3Y-DFS). Secondary endpoints include overall survival (OS) and safety. (NCT01283217) Results: As a result of early closure due to slow accrual, 153 patients of planned 290 patients were randomly assigned (75 patients to DS and 78 patients to SP) from 8 institutions for 31 months. The median follow up duration was 15.8 months (range, 0.8 to 36.2 months). There was no difference in DFS (HR, 1.088; 95% CI, 0.589 to 2.01; p=0.787) or OS (HR, 1.621; 95% CI, 0.707 to 3.720; p=0.254) between DS and SP. Most common grade 3 or 4 adverse event was neutropenia (42.7% among DS group and 38.5% among SP group, p=0.351). SP group suffered more grade 3 or 4 anemia (1.3% vs. 11.5%, p=0.037), where grade 3 or 4 hand-foot syndrome (4.1% vs. 0%, p=0.025) and mucositis (10.7% vs. 2.6%, p=0.001) were more common among DS group. Conclusions: Although the trial closed prematurely and had short follow up duration, S-1 plus cisplatin or docetaxel is an effective and tolerable option for patients with stage III advanced gastric cancer patients. Clinical trial information: NCT01283217.