Hospital birth records were sought for 104 men from a pool of male army conscripts with “normal” or “high” blood pressure when measured at 28 years of age. Of 77 men whose birth weight and date of the mother's last menstrual period before the pregnancy could be found, 25 had a resting diastolic blood pressure of ≥90 mm Hg. In 11 of these compared with nine of the 52 men with normal diastolic pressures their birth weights in relation to gestational age had been below the mean and 1 SD of a comparable Swedish population. The risk of increased diastolic blood pressure in early adult life was significantly higher among men who had been growth retarded at birth than among those whose birth weight had been appropriate for gestational age (odds ratio 3·63; 95% confidence interval 1·14 to 12·57). Being born small for gestational age may be a predictor of raised blood pressure in early adult life.