ObjectiveTo explore the proper time to initiation of adjuvant chemotherapy after radical resection for gastric cancer. MethodsWe searched electronically in PubMed, Embase, China National Knowledge Infrastructure, Wangfang database, and Chongqing VIP database for all relevant studies published before May 1st, 2018. The references included in eligible trials were also searched. All eligible studies were assessed and evaluated by two investigators working independently. The Meta-analysis was conducted using Stata 14 software. ResultsOur literature search included a total of 10 studies. There were 9 studies reporting overall survival (OS), in which 3 studies used a 4-week cutoff for delay from surgery to adjuvant chemotherapy, 4 shared a 6-week cutoff, and 2 studies shared an 8-week cutoff. There were 4 studies reporting disease-free survival (DFS). Initiating adjuvant chemotherapy beyond 4 weeks after surgery was significantly associated with worse OS [hazard ratio (HR)=0.42, 95% confidence interval (CI) (0.27, 0.65), P<0.001]. No significant benefit was found by starting adjuvant chemotherapy within 6 weeks or 8 weeks after surgery [HR=0.91, 95%CI (0.66, 1.26), P=0.577; HR=1.02, 95%CI (0.91, 1.14), P=0.744; respectively]. Four trials reporting DFS did not share a same cutoff delay from surgery to adjuvant chemotherapy, thus it was impossible to conduct a combined Meta-analysis. ConclusionThe initiation of adjuvant chemotherapy within 4 weeks after radical resection for gastric cancer may obtain better OS.