Individuals identified as at high risk of developing Hereditary Diffuse Gastric Cancer (HDGC) are advised to undergo prophylactic surgery - have their stomach removed - in their early twenties. Research with (older) cancer patients who undergo gastrectomy for curative reasons suggests that gastric resection has a number of physical and psychosocial sequelae. Because it is difficult to extrapolate the findings of studies of older cancer patients to younger healthy patients who are considering prophylactic total gastrectomy (PTG), the aim of this qualitative interview study was to determine the psychosocial implications of undergoing prophylactic surgery to manage genetic risk. Fourteen men and 13 women from the UK's Familial Gastric Cancer study who had undergone PTG were invited to participate in qualitative interviews. Most reported that undergoing surgery and convalescence was easier than anticipated. There was evidence that age affected experiences of PTG, with younger patients tending to report faster recovery times and more transient aftereffects. All saw the benefits of risk reduction as outweighing the costs of surgery. Surgery was described as having a range of physical impacts (disrupted appetite, weight loss, fatigue, GI symptoms) that had related psychological, social and economic implications. Those considering PTG need to be aware that its impact on quality of life is difficult to predict and negative sequelae may be ongoing for some individuals.