Background: According to the last report of the United Nations Office on Drugs and Crime (UNOCD), opiate use (including heroin) is 1.2% of the world population. In Iran, about 2 million people are drug addicts. Heroin reduces gastric motility and prolongs gastric emptying time and causes gastric dilation which can be a reason for gastric ischemia. Gastric ischemia is an uncommon condition due to the rich gastric blood perfusion and collateral arteries. As some studies show, gastric dilation can be the cause of gastric necrosis. Methods: A 22-year-old woman presented to our hospital with severe abdominal pain and several episodes of vomiting. The patient declared that she had a history of addiction to methamphetamine and heroin. Abdominal examination revealed a soft and non-distended abdomen with generalized tenderness, mostly in the hypogastric region without rebound tenderness. Abdominal radiograph revealed that the stomach was highly distended. Abdominal CT without contrast confirmed severe gastric dilatation. In endoscopy, multiple necrotic lesions were seen throughout the stomach and mostly in the proximal part. Our finding in the laparotomy was gastric necrosis in the proximal part, which resulted in a total gastrectomy. Esophagojejunostomy was performed with roux en y reconstruction after total gastrectomy. Conclusion: Opioids can increase the risk of gastrointestinal (GI) dysfunction and can increase the risk of infection in the GI tract. In our case, heroin abuse caused gastric dilation and massive gastric necrosis.