While existing research supports that participation in high‐school athletics is associated with better education and labor‐market outcomes, the mechanisms through which these benefits accrue are not well established. Using individual microdata collected daily, and team‐specific schedules, we retrieve estimates of the causal effect of high‐school athletic participation on absenteeism, suggesting that participation decreases absences, driven primarily by reductions in unexcused absences in boys. There are also strong game‐day effects in truancy, in both boys and girls, with truancy declines on game days more than offset by subsequent absenteeism. Important heterogeneity by race, gender, and family structure may serve to substantially reduce racial gaps in truancy and achievement. (JEL I21, L83)