Little is known about the prevalence of cerebral palsy (CP) within ethnic subgroups born in Britain. The Yorkshire Regional Cerebral Palsy Register has ascertained all cases of CP in children born within the Regional Health Authority boundary in 1985 to 1987 inclusive and diagnosed by 5 years of age. Birth registrations recorded by ethnic subgroups allowed us to determine the prevalence of CP within the Bradford District Health Authority (BDHA) boundaries by Asian and non-Asian ethnic subgroups. All the children with CP in BDHA were examined by one individual and careful family pedigrees recorded. We noted that BDHA had a high prevalence of CP; 3.87 to 4.16 per 1000. The prevalences in the non-Asian and Asian populations were 3.18, and between 5.48 and 6.42, per 1000, respectively. This difference was statistically significant (P=0.03). First cousin marriages occurred in 15 of the 39 Asian famines (51.7%) and nine of these families had another first or second degree family member with a similar type of CP to the index child. There was no consanguinity in the non-Asian families. These data highlight the increased need for services in some ethnic populations living in Britain and the likely genetic aetiology of a significant proportion of cases of CP in Asian families.