Objective To investigate the diagnosis and treatment of extra-adrenal pheochromocytoma(EAP). Methods The clinicsl data of 37 cases of EAP from April 2003 to April 2010 were retrospectively analyzed.Hypertension was observed in 31 cases.The typical triad of headache,palpitation and sweating was observed in 12 cases.The positive rate of plasma-free MNs and 24-hour urinary CA in diagnosing EAP was 96.8%(30/31) and 86.5% (32/37) respectively.The main localization diagnosis included ultrasonography,CT,MRI and 131I-MIBG,with positive rates of 91.7% (33/36),97.0%(32/33),90%(9/10) and 82.6%(19/23) respectively.Two patients underwent radiotherapy, and the remaining 35 cases underwent surgical treatment. Results Among the total of 37 cases,32 cases were single tumor,and five were multiple tumors.The anatomic locations of the single tumors were as follows: 14 wre adjacent to the abdominal aorta,seven in the bladder,four adjacent to the inferior vena cava,four adjacent to the renal hilum,two adjacent to the lilac blood vessel and one in the upper pole of the right kidney.Thirty cases underwent complete tumor resection,three cases underwent tumor resection plus right nephrectomy and two cases underwent partial cystectomy.Twenty-four cases were diagnosed benign and 11 cases were diagnosed malignant by pathological examination.Among 31 cases with preoperative hypertension,postoperative blood pressure returned to normal in 23 patients,blood pressure descended mildly in six cases and blood pressure was still hypertensive in two cases.Thirty-four patients were followed up for five months to seven years,during which five cases had tumor recurrence or metastases and five cases died postoperatively. Conclusions EAP is a rare neuroendocrine tumor and its accurate diagnosis is rather difficult.Plasma-free MNs and 24-hour urinary CA are important qualitative examinations.Ultrasonography,CT,MRI and 131I-MIBG scintigraphy are important methods for the localization of the tumor.Transperitoneal resection of the tumor is the preferred choice of management and adequate perioperative preparation is the key to a successful operation,including bringing down blood pressure,expanding blood volume and correcting arrhythmia.Patients with malignant EAP may be treated with 131I-MIBG after surgical therapy.