Late-stage gastric adenocarcinoma patients have a poor prognosis because of high recurrence rates.To improve long-term outcomes,perioperative chemotherapies are combined with surgery.Human epidermal growth factor receptor 2(HER2)overexpression had been noted in gastric cancer;therefore,trastuzumab has been used occasionally in this setting.A 63-year-old male Chinese patient,who was diagnosed with adenocarcinoma in the gastric antrum,as well as lymph node metastases along the left gastric and hepatic artery,and left adrenal area,was admitted to our hospital.HER2 expression was positive,and cluster amplification was detected in a fluorescence in situ hybridization assay.The patient received three cycles of a neoadjuvant trastuzumab/oxaliplatin/capecitabine regimen.He subsequently underwent distal gastrectomy,D2+lymphadenectomy,left adrenalectomy,cholecystectomy and BillrothⅡanastomosis.Treatment was continued with another five postoperative cycles of the same medication and trastuzumab application for 1 year.No recurrence has been observed 18 mo after the operation.Trastuzumab as perioperative and adjuvant medication,in combination with oxaliplatin and capecitabine for a HER2-overexpressing advanced gastric adenocarcinoma,led to recurrence-free survival of at least 18 mo after surgery. Late-stage gastric adenocarcinoma patients have a poor prognosis because of high recurrence rates. To improve long-term outcomes, perioperative chemotherapies are combined with surgery. Human epidermal growth factor receptor 2 (HER2) overexpression had been noted in gastric cancer; therefore, trastuzumab has been used occasionally in this setting. A 63-year-old male Chinese patient, who was diagnosed with adenocarcinoma in the gastric antrum, as well as lymph node metastases along the left gastric and hepatic artery, and left adrenal area, was admitted to our hospital. HER2 expression was positive, and cluster amplification was detected in a fluorescence in situ hybridization assay. The patient received three cycles of a neoadjuvant trastuzumab / oxaliplatin / capecitabine regimen. Next succeeding distal gastrectomy, D2 + lymphadenectomy, left adrenalectomy, cholecystectomy and Billroth Ⅱ anastomosis. Treatment was continued with another five postoperative cycles of the same medication and trastuzumab application for 1 year. No recurrence has been observed for 18 months after the operation. Trastuzumab as perioperative and adjuvant medication in combination with oxaliplatin and capecitabine for a HER2-overexpressing advanced gastric adenocarcinoma, led to recurrence-free survival of at least 18 months after surgery.