Neuroblastoma ranks third among pediatric malignancies.The case of a 3-year-old child is presented, who suddenly had frequent, unproductive, emetic cough; fever; and weight loss. Lung X-ray showed an opacity situated in the posterior superior mediastinum. Thoracic ultrasound revealed a slightly inhomogeneous, hypoechoic mass located in the posterior superior mediastinum. Computed tomography evidenced a tumor mass with homogeneous appearance in the costo-vertebral groove. Histological examination confirmed the diagnosis of ganglioneuroblastoma.Although history and clinical examination provided few elements, diagnosis was made based on imaging and histopathological examination.