The main aim of this study was to discover the number of children with heart defects registered for dental care under capitation in the north-east of England. Subsidiary aims were to compare percentage registrations of these children with those of a similar age in the general population and to investigate the involvement of the Hospital Dental Service (HDS) and Community Dental Service (CDS) in providing dental care for children with heart defects. A sample of all patients under the age of 18 years attending the northern regional cardiothoracic unit between 1st August 1990 and 31st July 1992 was obtained. Details were sent to the Dental Practice Board for analysis during September 1993. A separate analysis was undertaken to estimate the number of children receiving dental care at the dental hospital, Newcastle upon Tyne and within the CDS. A total of 930 children were identified during the study period. Only 38% of children were currently registered for capitation. Of the 930 patients 56 (6%) were registered at the dental hospital while 9% were estimated to be regularly attending the CDS. It is concluded that in the north-east of England, children with heart defects are registered under capitation at an unacceptably low level. They are less likely to be registered than children without this medical condition and it cannot be demonstrated that other dental services are making good the shortfall.