This study examined the controversial practice of grade retention and children'sacademic and behavioral adjustment using data from the Quebec Longitudinal Study ofKindergarten Children. We employed an autoregressive modeling technique to detect the impactof being held back during primary school on subsequent academic performance and behavioraldevelopment until age 12 years. The results indicate both a short- and long-term negativeinfluence on academic performance for boys and girls. Children's anxious, inattentive, anddisruptive behaviors persisted and, in some cases, worsened after grade retention. Theseprospective associations were long lasting and more pronounced when grade retention occurredearly in primary school. Boys were more vulnerable to the negative influence of grade retentionon academic performance and classroom disruptiveness. Disruptive behavior in girls wascomparatively less associated with long-term consequences than boys. Nevertheless, girlsexperienced both short- and long-term academic performance problems in the aftermath of graderetention. Children's prosocial behavior appeared unaffected by grade retention. Theseresults are independent of what would have been expected by the natural course of academic andbehavioral development.