Lower duodenal biopsies (LDB) are not taken at every oesophago-gastro-duodenoscopy (EGD). In the present study, biopsies from the endoscopic normal lower duodenum were checked as a measure of quality assurance. From 1996 to 2000, 9,955 EGD were performed and 4,199 LDB were taken (42.2 %). Of these, 667 showed pathological histology (15.9 %). A non-specific inflammation was seen in 537 cases and lymphangiectasia in 30 cases. Signs of indigenous sprue were described histologically in 6 LDB. In 4 of the 6 first diagnoses, the LDB was taken owing to clinical suspicion of malabsorption syndrome. Giardia lamblia could be detected in 22 patients. Only 6 of the 22 patients had diarrhoea. A total of 18 clinically relevant first diagnoses were made by LDB in asymptomatic patients with normal endoscopic findings in the duodenum. In order to make a relevant first diagnosis, 233 LDB had to be taken. LDB can be dispensed within EGD when there is neither diarrhoea nor loss of weight, and no anemia, iron deficiency, vitamin deficiency, macrocytosis, hypoproteinaemia, meteorism, joint symptoms or fever.