We report a case of diabetic ketoacidosis (DKA) associated with pheochromocytoma in a college student of 22 years of age who was admitted to hospital because of hyperglycemia and hypertension with palpitations and subsequently was found to have an adrenalin and noradrenalin secreting pheochromocytoma. A diagnosis was made and the patient's impaired glucose tolerance and hypertension improved by tumor excision. This is the first reported case of a noradrenalin-predominant pheochromocytoma with associated DKA. Although DKA has been thought not to occur with pheochromocytoma, the possible cause of DKA associated with pheochromocytoma is now described. It is important to point out, as a clinical manager, that severe hypertension is a very unusual concomitant of DKA in young people and is the main indication for further examination.