Primary gastric mucormycosis is a rare but potentially lethal fungal infection due to the invasion of Mucorales into the gastric mucosa. It may result in high mortality due to increased risk of complications in immunocompromised patients. Common predisposing risk factors to develop gastric mucormycosis are prolonged uncontrolled diabetes mellitus with or without diabetic ketoacidosis (DKA), solid organ or stem cell transplantation, underlying hematologic malignancy, and major trauma. Abdominal pain, hematemesis, and melena are common presenting symptoms. The diagnosis of gastric mucormycosis can be overlooked due to the rarity of the disease. A high index of suspicion is required for early diagnosis and management of the disease, particularly in immunocompromised patients. Radiological imaging findings are nonspecific to establish the diagnosis, and gastric biopsy is essential for histological confirmation of mucormycosis. Prompt treatment with antifungal therapy is the mainstay of treatment with surgical resection reserved in cases of extensive disease burden or clinical deterioration. We presented a case of acute gastric mucormycosis involving the body of stomach in a patient with poorly controlled diabetes and chronic renal disease, admitted with acute onset of abdominal pain. Complete resolution of lesion was noted with 16 weeks of medical treatment with intravenous amphotericin B and posaconazole.