Malignant peripheral nerve sheath tumors (MPNSTs) have rarely been reported to occur in the adrenal gland and all of the reported cases were associated with neurofibromatosis, pheochromocytoma or ganglioneuroma. We present here a case of MPNST in the bilateral adrenal glands without any history of neurofibromatosis or combined tumor. Histologic examination showed the tumor cells had a spindle to ovoid shape, they were arranged in sweeping fascicles and there were frequent mitotic figures. The immunohistochemical and ultrastructural features of the tumor are also presented. To the best of our knowledge, this is the first report in the English medical literature about MPNSTs in the bilateral adrenal glands without any history of neurofibromatosis or combined tumor.