Although ganglioneuroma is a relatively rare tumor of the sympathetic nervous system, detection of this tumor has increased as imaging techniques such as computed tomography and ultrasonography have become prevalent. We report 2 cases of ganglioneuroma found incidentally. Both tumors were 40 to 60 mm in size. Magnetic resonance imaging in 1 patient showed a homogeneous mass with a low signal intensity on T1-weighted imaging and a heterogeneous mass with a high signal intensity on T2-weighted imaging, both characteristic of neurogenic tumor. Therefore, we performed laparoscopic adrenalectomy. Histopathologic examination demonstrated that one tumor was located on the adrenal medulla, with the other in the extra-adrenal retroperitoneal space.