Early duodenal carcinoma is a rare entity. Most duodenal carcinomas are diagnosed at a more advanced stage. This report describes the case of a 59-year-old lady with an early duodenal adenocarcinoma diagnosed at check-up gastroduodenoscopy in an outpatient clinic who was referred to us for further investigation and management. The initial upper endoscopy at our department revealed a type IIa+c lesion in the proximal duodenum (10 - 12 mm diameter, flat elevated lesion with central depression). Using chromoendoscopy and magnification endoscopy the lesion could be well demarcated and neoplastic changes in the architecture of the intestinal villi could be detected. After submucosal epinephrine-saline injection, the lesion was removed by endoscopic resection without complications. Histopathological examination revealed the rare entity of an early duodenal carcinoma arising from incomplete-type gastric metaplasia in the duodenum. In summary, the presented paper describes a case of successful endoscopic treatment of an early duodenal carcinoma arising from incomplete gastric metaplasia.