Few cases of postoperative hypoglycaemia complicating the removal of a phaeochromocytoma have been reported in the literature. We reported one case of hypoglycaemia secondary to the removal of right phaeochromocytoma in a 30-year-old patient. Seven hours after the excision of the tumour, the patient developed a severe hypoglycaemia at 1.67 mmol x l(-1) revealed by seizures completely resolving in 24 h. The hypoglycaemia in this context resulted probably from the massive secretion of insulin by the beta cells of Langerhans islands due to the suppression of alpha-adrenergic inhibition. The prevention of this complication requires the repeated measurement of the capillary glycaemia in the postoperative period. An important supply of carbohydrate may be necessary to maintain a normoglycaemia.