Eosinophilic gastroenteritis is a rare disease of unknown etiology. It is characterized by eosinophilic infiltration of the bowel wall to a variable depth and symptoms associated with gastrointestinal tract. Recently, the authors experienced a case of eosinophilic gastroenteritis presenting as small bowel obstruction. A 51-year old woman was admitted to our hospital complaining of abdominal pain and vomiting. Physical examination revealed a distended abdomen with diffuse tenderness. Complete blood count showed mild leukocytosis without eosinophilia. Computed tomography confirmed a dilatation of the small intestine with ascites. An emergency laparotomy was performed for a diagnosis of peritonitis due to intestinal obstruction. Segmental resection of the ileum and end to end anastomosis were performed. Histologically, there was a dense infiltration of eosinophils throughout the entire thickness of ileal wall and eosinophilic enteritis was diagnosed. The patient recovered well, and was free from gastrointestinal symptoms at the time when we reported her disease.