"This essay presents tentative findings for the Sundsvall area of Sweden, which is being studied in a recent project on the decline of infant and childhood mortality in the Nordic countries. The focus is on the complete reproductive histories of single mothers and the life expectancies among infants born to women who at least once in their reproductive life history experienced the birth of an illegitimate child. In Sundsvall, industrialization only temporarily affected the illegitimacy ratio, but its effect was obvious even in agrarian parishes. The number of illegitimate children per woman remained relatively stable over time, with the exception of the town of Sundsvall. It was more common in the urban environment to give birth to several illegitimate children. Mortality was also higher among these infants, but the negative effects can be seen equally among both legitimate and illegitimate children."