OBJECTIVE: The aim of this study was to describe postoperative outcomes of total gastrectomy at our institution for patients with hereditary diffuse gastric cancer (HDGC). BACKGROUND: HDGC, which is mainly caused by germline mutations in the E-cadherin gene (CDH1), renders a lifetime risk of gastric cancer of up to 70%, prompting a recommendation for prophylactic total gastrectomy. METHODS: A prospective gastric cancer database identified 41 patients with CDH1 mutation who underwent total gastrectomy during 2005 to 2015. Perioperative, histopathologic, and long-term data were collected. RESULTS: Of the 41 patients undergoing total gastrectomy, median age was 47 years (range 20 to 71). There were 14 men and 27 women, with 25 open operations and 16 minimally invasive operations. Median length of stay was 7 days (range 4 to 50). In total, 11 patients (27%) experienced a complication requiring intervention, and there was 1 peri-operative mortality (2.5%). Thirty-five patients (85%) demonstrated 1 or more foci of intramucosal signet ring cell gastric cancer in the examined specimen. At 16 months median follow-up, the median weight loss was 4.7 kg (15% of preoperative weight). By 6 to 12 months postoperatively, weight patterns stabilized. Overall outcome was reported to be "as expected" by 40% of patients and "better than expected" by 45%. Patient-reported outcomes were similar to those of other patients undergoing total gastrectomy. CONCLUSION: Total gastrectomy should be considered for all CDH1 mutation carriers because of the high risk of invasive diffuse-type gastric cancer and lack of reliable surveillance options. Although most patients have durable weight loss after total gastrectomy, weights stabilize at about 6 to 12 months postoperatively, and patients report outcomes as being good to better than their preoperative expectations. No patients have developed gastric cancer recurrence after resections.