More than 2,000 10th grade boys were drawn in the 1966 sample and reinterviewed over 8 years (five waves of data collection), with the last interview conducted when the subjects were 24 years old. Data on delinquency were collected in all waves, but data on sports were collected only in the third wave (spring of the high school senior year). Measures of delinquency were based on self-reports. Athletic participation apparently had no effect on the delinquency of white males, but black athletes were more likely than black nonathletes to be delinquent at age 16. At age 18, however, the correlations were much smaller, until by the age of 24, black athletes were less likely than black nonathletes to commit offenses. This suggests that athletics exerts a notably positive influence on blacks, probably due to the building of self-esteem and the fulfillment of aspirations, factors known to prevent delinquency. 3 tables.