We experienced a case of paroxymal pheochromocytoma where the symptoms were successfully controlled by labetalol despite abnormally high blood levels of adrenalin before operation. The case was a 26-year-old male who had been treated at a local clinic under a diagnosis of intrahepatic hematoma for the past six years. At the time of investigation in our hospital, hypertension and palpitations were noted, and a right adrenal pheochromocytoma could be diagnosed by imaging and hormonal examinations. Catecholamine levels in both blood and urine were high, and in particular the adrenalin level was more than 300 times the normal one, which is higher than those in any other previously reported cases. For preoperative control, labetalol (an α β blocker) was found to be effective, and careful pre- and perioperative handling of this patient led to safe resection.