A prospective study of 320 Nigerian children was undertaken to determine their pattern of motor development by recording the age at attainment of 12 gross-motor milestones. The children were all born full term and were neurologically normal at birth. They were recruited in the first week of life and seen at regular intervals in a well-baby clinic, where their parents were questioned about the ages at attainment of milestones. Results show that most gross-motor milestones were attained at earlier ages by these children than by children studied to establish norms for the traditional tests of motor development that have long been in use. Our findings confirm several previous reports which emphasize the more rapid attainment of motor milestones such as 'sit without support', 'crawl', 'stand well alone' and 'walk well alone' by black as compared with white children. But, conversely, a number of transitional milestones such as 'roll over', 'pull self to stand' and 'stand holding on' were achieved later by children in this study than by their non-African counterparts. Girls in this study were slightly advanced, relative to boys, in their attainment of most milestones. The results of this study have been incorporated into a chart which can be used in well-baby clinics to detect children with motor delay.