The morbidity and mortality profiles of 831 non-adult skeletons from four contrasting sites in medieval and postmedieval England were compared to assess whether urbanization and later industrialization, had a detrimental effect on the health of the inhabitants. Failure in the population's ability to adapt to these environments should be evident in the higher rates of mortality, retarded growth, higher levels of stress, and a greater prevalence of metabolic and infectious disease in the urban groups. Non-adult skeletons were examined from Raunds Furnells in Northamptonshire, from St. Helen-on-the-Walls and Wharram Percy in Yorkshire, and from Christ Church Spitalfields in London. Results showed that a greater number of older children were being buried at the later medieval sites and that the skeletal growth profiles of the medieval urban and rural children did not differ significantly. A comparison of the growth profiles of St. Helen-on-the-Walls (urban) and Spitalfields (industrial) showed that the Spitalfields children were up to 3 cm shorter than their later medieval counterparts. At Spitalfields, cribra orbitalia and enamel hypoplasias occurred during the first 6 months of life, and 54% of the non-adults had evidence of metabolic disease. It is argued that differences in the morbidity and mortality of non-adults from urban and rural environments did exist in the past, but that it was industrialization that had the greatest impact on child health. Environmental conditions, urban employment, socioeconomic status, and changes in weaning ages and infant feeding practices contributed to differences in health in rural, urban, and industrial environments.