Ganglioneuroblastoma is a primary malignant tumor of the sympathetic nervous system. It usually occurs in children and is extremely rare in adults. Here, we report a case of an adrenal ganglioneuroblastoma in a 38-year-old man. The adrenal incidentaloma was surgically removed and pathologically diagnosed as a ganglioneuroblastoma. The characteristics were described, because it is an unusual tumor based on the published reports in adults. To the best of our knowledge, fewer than 50 cases of ganglioneuroblastoma and 19 cases of adrenal ganglioneuroblastoma, including this case, are reported in the literature.