Ganglioneuroma is a well-differentiated, benign tumor of the sympathetic nervous system. These tumors belong to a family of neoplasm that exhibit a wide range of differentiation, with neuroblastoma at one end and ganglioneuroma at the other. Because it share morphologic features with other both benign and malignant neural tumors, accurate preoperative diagnosis is often difficult. Nonetheless, it is critical for proper management. Fine needle aspiration cytology (FNAC) in the diagnosis of the ganglioneuroma has been a little documented. We describe a case of mediastinal ganglioneuroma in a 33-month-old girl. The diagnosis was suggested on FNAC and was confirmed by histopathologic examination later.