Ganglioneuroblastoma is a neuroblastic tumour arising from primitive sympathetic ganglion cells. Neuroblastic tumours have a broad-spectrum of clinical behaviour from spontaneous regression to benign ganglioneuromas to metastatic dissemination. We present a case report of 2-year of girl who had a provisional diagnosis of an ovarian mass. Exploratory Laparotomy in a peripheral center revealed a retroperitoneal mass crossing the midline extending into the pelvis. She was unresectable and histopathology showed Ganglioneuroblastoma Stage III. She was managed with chemotherapy and repeat surgery for residual disease. Surgery remains the choice of treatment for neuroblastic tumours.