Multiple endoscopic biopsies in the descending duodenum are usually recognized as the standardized method for the evaluation of mucosal changes in coeliac disease. Generally, the duodenal bulb is not considered a useful site for biopsies, due to some difficulties in histological evaluation. A case in which the diagnosis of coeliac disease was possible only with the aid of biopsies in the duodenal bulb is reported; noteworthy, this unusual site for biopsies was strongly suggested by the presence of a mosaic-like endoscopic appearance. Only few cases (mainly in childhood) have been reported in which diagnosis was made with the aid of biopsies in the duodenal bulb. This occurrence suggests that performing biopsies only in the descending duodenum may not be sufficient in some patients, and raises the question of whether obtaining specimens both from the first and the second part of the duodenum might be a more correct and complete approach to this problem.