Eosinophilic gastroenteritis is an inflammatory pathology with an unknown etiology characterised by the presence of an eosinophil infiltrate on the intestinal wall. The symptoms (bleeding, occlusion, fistulae, etc.) may lead to surgery even if the best treatment is medical. Endoscopic examination with specific multiple biopsies is indispensable for the diagnosis of the pathology. The authors report the case of a 2-month-old baby suffering from intermittent pyloric obstruction secondary to eosinophilic gastroenteritis which was wrongly interpreted as hypertrophic stenosis of the pylorus.