The average blood pressure measured in a representative sample of 8th grade juveniles (14-16 years) was 120/70 mm Hg. Mean systolic pressure was 5 mm Hg higher in boys. The 90th percentile was 135/80 mm Hg for both sexes. Systolic and diastolic pressure rose with increasing body weight. Correlation with height was less obvious. Difference in weight could not account for all the sex difference in blood pressure. Association of sexual maturation with higher blood pressure values was more pronounced in boys.