Gastric stump carcinoma after gastric surgery for benign disease is now widely recognized as a distinct clinical entity. The stump carcinoma was often found to be localized to the anastomosis, known to be the site with severe duodenogastric reflux. For this reason, duodenogastric reflux, including the reflux of bile and pancreatic juice, after a Billroth II procedure for benign disease is frequently discussed as an important factor related to the development of stump carcinoma. Many experiments have implicated bile acids, the main component of the duodenal juice, in gastric carcinogenesis. In particular, rat models without the use of the carcinogen, N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), showed adenocarcinoma in the remnant stomach that was related to the severity of duodenogastric reflux. However, human data are, inevitably, much less consistent. Whether the incidence of stump carcinoma is higher than that of gastric carcinoma in general is still controversial. Concerning the histogenesis of stump carcinoma after benign disease, a relationship between gastritis cystica polyposa (GCP) and gastric type adenocarcinoma has been suggested. Recently, the population at risk of gastric stump carcinoma for benign disease has been diminishing significantly, and the incidence of gastric stump carcinoma after surgery for malignant disease has been increasing. The influence of duodenogastric reflux in the gastric remnant after malignant disease may differ from its influence in the gastric remnant after benign disease. Further clinical study is needed to elucidate the pathogenetic factors involved in gastric stump carcinoma.