To establish the value of screening children for hypercholesterolemia in terms of identifying future adults with hypercholesterolemia, we studied 611 individuals 9 years after they were initially screened at age 12 years. They represent 61% of a stratified sample of the original cohort, which was drawn from all seventh graders in a countywide school district. Overall, the correlation between baseline and follow-up cholesterol concentration was r = 0.52 (P less than 0.0001). Forty-nine percent of the top cholesterol quintile at baseline were similarly placed at follow-up, with 70% in the top two quintiles. Children who dropped out of the top quintile had lower body mass index at follow-up (P less than 0.05), were less frequently smokers, and tended to be more active than those who were only in the top quintile as adults.