We describe three patients with celiac disease complicated by adenocarcinoma of the small intestine, and summarize the 36 cases of this association that have been reported. Retrospectively we found an increased risk (relative risk 25-250) of developing adenocarcinoma of the small intestine in patients with celiac disease in the region of Winterthur (north-east Switzerland). We therefore suggest that celiac disease be considered a premalignant condition not only for malignant lymphoma and gastrointestinal tumors, but also for adenocarcinoma of the small intestine. Synchronous or metachronous development of carcinoma in one of our patients and in two cases reported in the literature offer further evidence that celiac disease is a premalignant condition for adenocarcinoma of the small bowel. In several patients celiac disease was diagnosed only after diagnosis of the carcinoma. With regard to asymptomatic or subclinical celiac disease, it seems justifiable to search for possible underlying celiac disease in all patients with established diagnosis of adenocarcinoma of the small intestine.