A total of 124 mothers from three cultural groups living in the same British city were asked to give the ages at which they expected their one-month-old infants to achieve three motor milestones. Jamaican mothers expected their infants to sit and walk much earlier than their English and Indian counterparts. The Indian mothers gave later estimates for crawling than those of the other two groups. The actual ages at which the abilities were attained closely reflected the cultural differences in expectations between the Jamaican and English mothers. Jamaican mothers were particularly accurate in predicting sitting age. These results are discussed in relation to cultural theories of child development, together with their implications for child health in multicultural societies.