Afferent loop obstruction associated with remnant gastric cancer is extremely rare, with only 7 cases reported to our knowledge in Japan. A 62-year-old man who underwent distal gastrectomy for a duodenal ulcer 37 years earlier, was admitted for nausea and vomiting. Laboratory studies revealed jaundice and hyperamylasemia and abdominal CT scans showed a fluid-filled dilated afferent loop and mass lesion near the gastrojejunostomy. Emergency upper gastrointestinal endoscopic examination showed type 3 gastric cancer at the gastrojejunostomy and the afferent limb was obstructed due to the cancer, so we could not insert the drainage tube into the afferent loop. We diagnosed afferent loop obstruction associated with remnant gastric cancer. Emergency surgery showed Billroth-II reconstruction by the retro-colic route in the primary operation, and an extremely dilated and dark red afferent loop. The tumor was found to have invaded the tail of the pancreas and the transverse mesocolon. Total gastrectomy and D2 lymph node dissection with resection of the tail of the pancreas and spleen was performed.