A 61-year-old female was referred to The First Affiliated Hospital, College of Medicine, Zhejiang University (Hangzhou, China) due to a right adrenal tumor. A pre-operative transcutaneous fine-needle aspiration biopsy and right adrenalectomy were performed, and pathological analysis resulted in the diagnosis of pleomorphic rhabdomyosarcoma (RMS). Primary pleomorphic RMS of the adrenal gland in an adult is a rare condition. To the best of our knowledge, this is the first case of pleomorphic RMS of the adrenal gland in an adult diagnosed by light microscopy and immunohistochemical stains.