A 74-year-old male presented with melena and fatigue, without fever or abdominal pain. Laboratory examination revealed anemia, leukocytosis, elevated C-reactive protein levels and conjugated hyperbilirubinemia with elevated liver enzymes. Upper endoscopy identified blood in the stomach and duodenum and a 6 mm hole in the anterosuperior surface of the duodenal bulb with spontaneous drainage of a bloody brownish content. The mucosa surrounding the hole was normal and there was a discrete mucosal flap that throbbed with air insufflation. Abdominal computed tomography identified a fistulous tract between the duodenal bulb and the gallbladder with a 2 mm caliber, suggesting a cholecystoduodenal fistula. Diagnosis is often difficult because symptoms are nonspecific and variable but gastrointestinal bleeding is a rare clinical presentation.