Gastric mucormycosis is a rare and life-threatening fungal disease, caused by fungus in the order Mucorales. While rhino-cerebral and pulmonary forms are common, gastric mucormycosis is an uncommon site for the disease. We diagnosed gastric mucormycosis in a 41-year-old female who had severe multiple trauma, including cardiac rupture, due to a traffic accident. Eighteen days after hospitalization, she passed 800 mL of melena over one day. We performed upper esophagogastroduodenoscopy (EGD) and found a huge gastric ulcer with bleeding. Histopathological examination identified non-septated and right-angled branching fungal hyphae, and we diagnosed gastric mucormycosis. We recommended total gastrectomy to her but she refused the operation, so she was treated with liposomal amphotericin B for 53 days. After two months of treatment with liposomal amphotericin B, we again performed EGD and found a healed gastric ulcer. After four months, with another EGD, we found that the gastric mucormycosis was completely healed.