In a large prospective study of cardiovascular disease in 7735 middle-aged men--the British Regional Heart Study--the 443 subjects who experienced a major ischaemic heart disease event within 7.5 years of follow-up were on average 1.6 cm shorter than the other men (p less than 0.001). The risk of heart attack was approximately twice as great in the shortest quintile of men compared with the tallest quintile. When a number of recognized risk factors for ischaemic heart disease were taken into account--age, social class, serum total cholesterol, HDL-cholesterol, systolic blood pressure, cigarette smoking--there was a marked reduction in the risk of heart attack associated with height. When a measure of lung function (FEV1 not standardized for height) was adjusted for in addition to these risk factors, the height-related risk of heart attack disappeared. Indeed, FEV1 alone was sufficient to account for most of the association between height and the risk of heart attack.