The study reported here was designed to test the ability of the theory of planned behavior to mediate the effect of parental supervision on adolescents' intentions to violate driving rules. Method: A representative sample of 1,654 adolescents completed questionnaires during individual and anonymous interviews carried out at their schools. Results: Results showed that age, gender, prior risky driving-behavior, and parental supervision significantly predict intentions to violate driving rules. Attitude and the subjective norm partially mediate the effect of age, prior behavior, and parental supervision. Perceived behavioral control does not predict intention and is not predicted by other variables. Impact: The results suggest that social cognitive variables partially mediate the effect of parenting practices such as supervision.