We performed a retrospective review of five patients with carotid body tumors at our institution between 1997 and 2005. Out of the five patients, three patients were treated by surgical resection of the tumor, and 2 patients were observed. It would seem that it is difficult to suspect this disease based only on the clinical findings, because the disease was suspected in only one patient at the first medical examination. Imaging tests are important for establishment of the diagnosis. Color Doppler sonography and MR angiography in addition to MRI are useful. Angiography and balloon Matas test are important for selection of candidates for the operation. The resected tumors were all classified in Shamblin's group II. Delayed cerebral infarction was caused in one patient postoperatively, although the carotid artery was preserved. The dissection in a tumor-adventitial plane using the bipolar coagulation technique under the microscope was performed in the other two cases. Histological examination of the specimen revealed no tumor cells in the excision stump. Dissection in the tumor-adventitial plane using bipolar coagulation under the microscope is important for carotid artery preservation and radical resection of Shamblin's group I and II tumors. It is necessary to compare the risk of the operation with the problems of observation in the process of decision making and to achieve reliable informed consent. Moreover, it is necessary to examine the indications for operation in individual cases referring to the age, past history, expected Shamblin's classification, and result of the balloon Matas test. A multidisciplinary approach should be used, involving the fields of otolaryngology, radiology, neurosurgery and vascular surgery to treat these patients.