The high incidence of cerebral palsy and the increase in the spastic quadriplegic and dyskinetic syndromes over the two periods is very disturbing. The absence of a fall in spastic diplegia is equally distressing, more especially in view of the consistent decline in recently published studies (Hagberg et al., 1975; Davies and Tizard, 1975; Brown, 1977). Coinciding with a fall in perinatal mortality rate, it might be postulated that 'improved' care in inadequately equipped and staffed 'intensive' care units is keeping alive babies who might otherwise have died. Two other possible causes must be kept in mind: (a) children with severe cerebral palsy who died in the first period, having been classified as severely mentally handicapped only, (b) inadequacy of special accomodation for severely handicapped children in the earlier years of this study. There was a slight fall in perinatal aetiology. However, many treatable or preventable factors kept recurring, i.e., asphyxia-usually acute and treatable by intubation and ventilation-convulsions, hypoglycaemia and hypothermia. Prenatal and untraceable factors increased. Rubella and toxoplasmosis had been identified as the causative agents in six children, and would probably have been diagnosed more frequently, had they been actively sought after, in the earlier years of the study. Foetal malnutrition was identified in a surprisingly high percentage of cases. These provide support for Hagberg's (1975) contention that prenatal mechanisms are quantitatively the most important pathogenic factors in cerebral palsy and severe mental retardation. There was no change in the number of low birth weight or small for gestation babies in the two periods, reflecting to some extent the relatively large low birth weight rate in the area. Better antenatal care and screening procedures, together with changing patterns of obstetrical management of the mother in premature labour, should help to alleviate this problem. Continuous improvement in social standards will make an equally important contribution. Previous documented reports on the global level of intelligence amongst the cerebral palsy population would appear more optimistic than the findings of this regional study. Reports of assessments from different centres suggest that less than 50% of children with cerebral palsy are functioning in the handicap range (I.Q. <70), 45% in the Birmingham series, 47% Liverpool, 49% New Jersy, 49% Dundee, 41% Sheffield series (Holt and Reynell, 1967). The figure of 64% in this regional study is indeed very unfavourable, and it must be remembered that nearly half of these were in the moderate to severe range. The fact that this series includes all cases of cerebral palsy, many of whom might be classified as mentallly handicapped only and usually excluded from studies of this kind, may be a major factor in the apparent discrepancy.