The appendiceal abscess is a common complication of acute appendicitis and usually is located in the right lower quadrant of the abdomen. An epigastric appendiceal abscess has never been reported at an unusual location. We experienced an unusual case of a 49-year-old man with an epigastric appendiceal abscess. Initially, this abscess was suspected to be a pancreatic abscess. Abdominal CT scan and barium enema demonstrated a hyperrotated cecum with an appendiceal abscess in the left upper quadrant of the abdomen. An gastroscopy revealed a small fistula-like lesion with purulent coating at the bulging posterior gastric wall. The abscess resolved spontaneously. We believe that the abscess drained into the stomach through a small fistula between the stomach and abscess cavity. There was no recurrence for over 6 months.