In 10 patients presenting with acute recurrent dysphagia, seen over a 4-year period, idiopathic, eosinophilic esophagitis (IEE) was diagnosed. The diagnosis was confirmed histologically. Dysphagia of other causes or other diseases causing eosinophilic infiltration was ruled out. Endoscopy showed discrete white structures in the esophagus which were partly finely reticular or plaque-like in 9 of the 10 patients. Of these one had a web and another a mucosal ring. Peripheral eosinophilia and elevated IgE-levels were found in 70% of the cases. To date IEE has been thought to be a rare disorder. Emerging evidence suggests its prevalence has been underestimated. It may also be the most frequent form of eosinophilic gastroenteropathy. The flat, only endoscopically visible form may be more common than the proliferative type. With knowledge of the typical history and of the distinct endoscopic pattern, and with adequate diagnostic workup, the disease will be found more often in the future. Prompt diagnosis also avoids further diagnostic procedures and permits rapid remission through treatment with steroids and antihistamines.