The relation between adult body height and two socio-economic factors (income and educational level) was studied in a large, ethnically homogenous population. In the period 1980-1983 all persons aged 40-54 years (born 1926-1941) in two Norwegian counties were invited to a cardiovascular screening. Ninety per cent (or 38162 persons) of those invited attended and had their height measured. Information concerning income and education was available at an individual level from the 1980 national census. Strong, positive relations were found between mean body height and the socio-economic factors, relations that probably are due to conditions during growth influencing both height, attained education and income abilities. The difference between highest and lowest educational class was 3.3 cm in men and 3.2 cm in women, and between highest and lowest income group 3.5 cm in men and 4.2 cm in women. These differences could not be explained by the strong cohort effect of increasing height in the successive birth cohorts from 1926 to 1941 which also was evident. It should be emphasized that height only could explain a small fraction of the variance in the socio-economic factors and is thus not a usable indicator of an individual's socio-economic status. However, it might contribute with important information concerning social inequalities in groups or population.