This article examines the health and height of men born in England and Wales in the 1890s who enlisted in the army at the time of the First World War, using a sample of recruits from the army service records. These are linked to their childhood circumstances as observed in the 1901 census. Econometric results indicate that height on enlistment was positively related to socio-economic class, and negatively to the number of children in the household in 1901 and the proportion of household members who were earners, as well as to the degree of crowding. Adding the characteristics of the locality has little effect on the household-level effects. However local conditions were important; in particular the industrial character of the district, local housing conditions, and the female illiteracy rate. These are interpreted as representing the negative effect on height of the local disease environment. The results suggest that changing conditions at both household and locality levels contributed to the increase in height and health in the following decades.