We report the case of a recurrent intradural spinal teratoma in a 44-year-old woman. Histological examination showed the lesion to be composed entirely of mature elements including an argyrophil carcinoid tumour. Electron microscopy showed the neoplastic cells to possess the ultrastructural features of a foregut type APUDoma. Gamma enolase, a marker of APUD cells, was demonstrated in the neoplasm by the peroxidase-antiperoxidase technique. This method was also used to demonstrate the presence of cytokeratins in the neoplastic cells and the squamous and columnar epithelia within the teratoma. These results are consistent with the suggestion that APUD cells of foregut type may be of endodermal rather than neuroectodermal origin.