Background The feasibility of the use of the enhanced recovery after surgery (ERAS) protocol in patients with gastric cancer remains unclear. Methods This study was a single-center, prospective randomized trial involving patients with gastric cancer undergoing curative gastrectomy. The primary end point was the length of postoperative hospital stay. Secondary end points were the postoperative complication rate, admission costs, weight loss, and amount of physical activity. Results From July 2013 to June 2015, we randomized 148 patients into an ERAS protocol group (n = 73) and a conventional protocol group (n = 69); six patients withdrew from the study. The hospital stay was significantly shorter in the ERAS protocol group than in the conventional protocol group (9 days vs 10 days; P = 0.037). The ERAS protocol group had a significantly lower rate of postoperative complications of grade III or higher (4.1% vs 15.4%; P = 0.042) and reduced costs of hospitalization (JPY 1,462,766 vs JPY 1,493,930; P = 0.045). The ratio of body weight to preoperative weight at 1 week and 1 month after the operation was higher in the ERAS protocol group (0.962 vs 0.957, P = 0.020, and 0.951 vs 0.937, P = 0.021, respectively). The ERAS protocol group recorded more physical activity in the first week after surgery.Conclusions The ERAS protocol is safe and efficient, and seems to improve the postoperative course of patients with gastric cancer.