74,000 18-year-old men who went through the medical examination for the military draft procedure in the greater Stockholm region during the years 1969-1978 were divided into 63 areas of residence. Means of systolic and diastolic blood pressures, as well as heart rate, height, muscle strength and reasoning test results varied significantly across areas. In a univariate analysis, significant correlations were found between high average systolic blood pressure in an area on one hand and low median income and high proportion of subjects on social welfare in the area on the other hand. In a multivariate analysis these associations were partly explained by a tendency of areas with relatively poor socioeconomic conditions to have high average relative weight, high mean muscle strength and poor average reasoning test results. All of these variables were associated with high average systolic blood pressure. The findings are discussed in relation to ecological mechanisms. Somatic and psychological development during childhood is associated with educational environment at school and leisure activities. Areas with poor socioeconomic conditions and high average systolic blood pressure were those which tended to have high rates of migration.