Although adrenal ganglioneuroma (GN) is a rare tumor originating from the neural crest tissue of the sympathetic nervous system, detection of this tumor has increased, as imaging procedures such as ultrasonography (US) and computed tomography (CT) have become prevalent. The clinical presentation for most patients is asymptomatic, and most of those tumors are hormone silent. We describe a case of adrenal GN incidentally diagnosed in a 68-year-old female patient. Physical examination, routine laboratory studies, and hormonal tests were within normal ranges. Abdominal CT and magnetic resonance imaging showed a solid oval tumor approximately 6 x 4 cm in the left adrenal gland without remarkable signs of malignancy. Left adrenalectomy was performed for treatment purposes. Histological diagnosis of the tumor was a ganglioneuroma originating from the adrenal medulla. Adrenal GN occurs rarely in adults and preoperative diagnosis is difficult, especially in asymptomatic cases. It needs careful evaluation and surgical treatment. According to our knowledge, this is the fifth case of adrenal GN in an adult patient from Turkey in English literature.