1507 newborns were examined neurologically at term; 80 of them were found to be abnormal. These were re-examined at 4 years of age, together with a control group of neonatally normal children. One child in the study group died, 8 were severely handicapped, 10 were mildly abnormal (MND = minor neurological dysfunction). In the control group 6 children turned out to have MND at 4 years. All but one of them had suffered interval complications, mainly before the age of 18 months. The relationships between the follow-up findings and the obstetrical, neonatal neurological and paediatric observations, family history and interval data are discussed. There appears to be a cumulative effect. The parents' reports on behaviour at age 4 suggest differences between the neonatally abnormal and normal groups, especially when MND is present at 4 years.