Two studies were designed to examine the relations between early growth and cardiovascular disease in adult life. The first study was a survey of pelvimetry in 1,615 men and women aged 50 yrs or more living in 8 English towns. The mean diameters at the pelvic inlet were smaller in towns with higher SMR's for cardiovascular disease. In both sexes the pelvises of those aged 75 or more had a lower brim index than the pelvises of those who were younger. The second study followed up 449 infants bom in Preston during 1935-1943 who were still living in Lancashire. In both sexes systolic and diastolic pressures were strongly related to placental weight and birth weight. Mean systolic pressure rose by 15 mmHg as placental weight increased from 11b or less to greater than 1.51b, and fell by 11 mmHg as birth weight increased from 5.51b or less to greater than 7.51b. These relations were independent of each other, and of the observed effects of higher body mass index and alcohol consumption. Analysis ofsubjects bom after 38 weeks completed gestation showed that for those with placental weights of 1.25 lb or less, mean systolic pressure rose by 13 mmHg as ponderal index (w/P) at birth fell from greater than 14.75 to 12 or less, while for those with placental weights of greater than 1.25 lb , mean systolic pressure rose by 14 mmHg as head circumference/length increased from less than 0.65 to 0.7 or more. Growth in early life, reflected in the size of the adult bony pelvis, is related to risk of cardiovascular disease. The intrauterine environment, through an effect on intrauterine growth, has an important effect on blood pressure in adult life. Two groups of babies, characterised by birth measurements, have been identified as being at increased risk of raised blood pressure in adult life.