Abstract We report the case of a 23-year-old immunocompetent patient who presented at the emergency department of a Brazilian hospital with epigastric pain and fever. After an investigation that included a computed tomography scan and upper gastrointestinal endoscopy with biopsy, a diagnosis of mucormycosis was established. The patient exhibited favorable progress after surgery and antifungal therapy. Mucormycosis is a rare condition that usually affects immunocompromised patients, with a high mortality rate of up to 85%. Correct diagnosis and fast initiation of therapy are required to ensure improved patient prognosis.