OBJECTIVE To investigate infant care practices in a small ethnic minority population within Britain that might suggest possible factors contributing to the low incidence of the sudden infant death syndrome in Asian populations. METHODS Ethnographic interviewing, a qualitative comparative method drawn from social anthropology. METHODS Central Cardiff. METHODS Non-random sample of 60 mothers of Bangladeshi or Welsh ethnic origin and working or middle class occupational status, who had infants under one year old. None of the families interviewed had experienced a sudden infant death. RESULTS Broad cultural contrasts emerged as a series of themes from the interview data: living patterns, family networks, sleeping patterns, and concepts of time and dependence. CONCLUSIONS Bangladeshi infants were cared for in a consistently rich sensory environment; Welsh infants, in contrast, were more likely to experience alternating periods of high and low sensory input. Long periods of lone quiet sleep may be one factor that contributes to a higher rate of sudden deaths in white than in Asian infants.