Parenting style has been extensively analyzed as a contributor to juvenile delinquency in the criminological literature, but no research to date has assessed the prevalence of parenting style changes during adolescence or the influence of such parenting style changes on juvenile delinquency. Drawing from the life course theory, the results show that parenting style transitions are common across the first and third waves of the National Longitudinal Survey of Youth, 1997. Furthermore, specific parenting style shifts are associated with changes in juvenile delinquency, most notably the shifts characterized by a decrease in responsiveness or an increase or decrease in demandingness. Last, changes in maternal attachment associated with parenting style changes partially mediate the effect of such transitions on delinquent outcomes.