A 72-year-old male gastric cancer patient with outlet obstruction underwent laparoscopic exploration. The examination disclosed intraperitoneal free cancer cells with no overt peritoneal, lymphatic, or hepatic metastasis. The patient underwent laparoscopy-assisted gastrojejunostomy (LAGJ) and started chemotherapy with S-1 plus cisplatin on postoperative day 13. Three course of the chemotherapy shrank the tumor markedly. Then, the patient underwent gastrectomy with a curative intent. Laparotomy revealed no intraperitoneal free cancer cells, and microscopically complete resection was achieved. The patient received S-1 chemotherapy as postoperative adjuvant treatment for 1 year, and is still alive with no evidence of peritoneal recurrence. LAGJ followed by S-1 plus cisplatin is one of the optional treatments that should be considered for patients with outlet obstruction as it may widen opportunities for potentially curative resection.