Pheochromocytoma is a rare tumor of chromaffin tissues most commonly arising from the adrenal medulla. We retrospectively reviewed the records of 38 patients with pheochromocytoma who underwent surgical treatment between 1977 and 2004 at our Yokohama City University Medical Center and Yokohama City University Hospital. Twenty two patients (57.9%) were females and 16 (42.1%) were males. The most frequent symptoms were headache (58%). One patient had bilateral adrenal tumors and pathological examination revealed malignant pheochromocytoma. Six patients had an extra-adrenal tumor and in 2 patients the tumor occurred in the urinary bladder. Twelve patients (31.6%) had sustained hypertension, 21 patients (55.3%) had paroxysmal hypertension and 5 patients (13.1%) remained normotensive. The 24-h urinary total metanephrines and vanillylmandelic acid (VMA) were the most sensitive biochemical tests for the diagnosis of pheochromocytoma. The sensitivity of urinary total metanephrines was 92.0% for all the patients and was 92.3% for the patients without paroxysmal hypertension. Fifteen patients had intraoperative hypertensive reactions in the surgical manipulation or hypotension after tumor resection. This group had more urinary excretion of VMA before surgery, compared with that with stable intraoperative blood pressure (p < 0.005).