We present a rare late-onset (after 24 years) complication of gastric surgery with a combination of afferent loop syndrome associated with a large duodenal stone. The patient, who had undergone Billroth II partial gastrectomy for benign ulcer 24 years before, developed abdominal pain in the right upper quadrant, associated with nausea, vomiting, and high grade fever. Abnormal laboratory values included elevated liver function test, suggesting a pressure-related phenomenon. Leukocytosis and a high level of platelets were also found. Only computed tomography and endoscopy of the upper gastrointestinal tract confirmed the diagnosis of a huge stone in the dilated duodenal afferent loop. To our knowledge, a case like this has not been reported previously in the literature.