Two children with the coexistence of long segment Hirschsprung's disease, ganglioneuroblastoma with Ondine's curse in one case and autonomic nervous system impairment in the other are presented. All lesions may be related to aberrations of neural crest cell growth, their migration, or differentiation. A genetic etiology, and the link between Hirschsprung's disease and multiple endocrine adenomatosis is discussed. The combination of Hirschsprung's disease and a neurocristopathy strongly suggests that exploration of the autonomic nervous system and APUD system be carried out.