BACKGROUND: At the end of the 19th century, infant mortality was high in urban and rural areas in Sweden. In Stockholm, the mortality rate was particularly high among foster children. This study addresses the importance for health of targeted public policies and their local implementation in the reduction of excess mortality among foster children in Stockholm at the turn of the 19th century. In response to public concern, a law was passed in 1902 on inspections of foster homes. Stockholm city employed a handful of inspectors who visited foster homes and advised parents on child care and feeding. METHODS: Analysis of historical records from the City of Stockholm was combined with epidemiological analysis of mortality rates and hazard ratios on individual-level data for 112 746 children aged <1 year residing in one part of Stockholm between 1878 and 1925. Hazard ratios of mortality were calculated using Cox' regression analysis. RESULTS: Mortality rates of foster infants exceeded 300/1000 before 1903. Ten years later the mortality rates among foster children had declined and were similar to other children born in and out of wedlock. Historical accounts and epidemiological analysis of individual-level data over a longer time period showed similar results. CONCLUSIONS: Targeted policy measures to foster children may have potentiated the positive health effects of other universal policies, such as improved living conditions, clean water and sanitation for the whole population in the city, contributing to an equalization of mortality rates between different groups.