Developmental screening was applied during infancy to a birth cohort of 1,000 coloured infants born consecutively in Cape Town. The developmental progress of a sample of 187 children randomly selected from the cohort was followed over a period of 5 years. The value of the use of developmental screening is questioned, since 4 of the children in the cohort with major handicap had been diagnosed before the first screening was carried out and a 5th child with deafness was not detected by the screening process. Developmental milestones were similar to those studies reported in the literature. At 12 months the development correlated best with family stability. Language development at 30 months was associated with mother's education and family stability and reflected a general lag in verbal skills. By 5 years there was a good correlation between development and social indicators, particularly income and mother's education.