The family situation for mothers, in three areas differing in degree of urbanization and an upper middle class control group, in Lahore, Pakistan was described. Area differences in socio-economic, family composition, and housing and sanitary conditions were investigated. Data from a longitudinal sample (n = 1476 newborns) were compared with data from a cross-sectional population survey (n = 2998 families). Risk factors for child mortality and morbidity were common in the village and periurban slum area; conditions were somewhat better in the urban slum community. The sample was concluded to be representative of the population in the three areas and also for Pakistan in general. Two indices for cross-study comparisons were proposed, one for socio-economic background and the other for housing standard. The two indices were shown to be related to maternal weight for height at 9 months of pregnancy in the urban slum area; the socio-economic level was also functionally related to the weight for height measure in the village. The lower socio-economic and housing standard level, the lower was the mothers' relative weight just before childbirth. The findings were discussed in terms of risk factors for infant mortality, morbidity and psychological development.