A case of allergic granulomatous angitis (AGA) complicated with the perforation of the ileum was described. A 52-year-old male had suffered from bronchial asthma since 1990, and two years later he had severe attack of asthma and manifestation of systemic vasculitis. He was diagnosed a AGA with the symptom of vascultitis, history of asthma, and the abnormal hematological findings (WBC 13000/mm3, eosinophilia 11.1%, IgE 1290U/ml, RA 2+). The treatment with adrenal corticoid hormone was started. In April 1992, he complained of severe right lower abdominal pain. He was diagnosed the gastrointestinal perforation by the abdominal X-ray examination and emergency operation was performed. Two ileal perforations were found at the operation and the ileectomy was carried out. Only 11 cases of AGA complicated with the gastrointestinal perforation have ever been reported in Japan. The perforation occurred often at the small intestine and the poor prognosis was referred. The administration of adrenal corticoid hormone should be continued after operation.