A patient presented at the age of 72 years with a life long history of at least 60 years of abdominal crises described by the patient as 'bilious vomiting or migraine'. However, a careful clinical and family history suggested a diagnosis of hereditary angioneurotic oedema and this was confirmed by complement studies. Treatment with oral ethinyltestosterone (Danazol) was successful in abolishing her attacks, initially at a dose of 600 mg. per day and laterally at the low dose of 200 mg per day.