A case of primary ganglioneuroblastoma located in the anterior mediastinum is described. The tumour was found incidentally at autopsy in a 61-year-old woman who died of coronary artery thrombosis. There was no evidence of metastases. Histologically the tumour was a ganglioneuroblastoma of the diffuse type. There was no pure neuroblastomatous tissue present and maturation to ganglioneuroma was not observed. Regressive changes like fibrosis and calcification were present. Review of the literature failed to reveal any recorded cases of ganglioneuroblastoma occurring in the anterior mediastinum. Although ganglioneuroblastoma occurs predominantly in children, 24 cases occurring in adults have been reported in the literature.