This study examined differences in adolescents' levels of autonomy as a function of parenting and parental involvement practices and the adolescents' year-end grade point averages. Participating were 872 adolescents, with a mean age of 14.45 years, attending 5 French-speaking public high schools in Quebec, Canada. Measures were subjects' general year-end grade point averages, the Student Report of Autonomy, the Student Report of Parenting Style, and the Student Report of Parent Involvement. The findings indicated that adolescents' autonomy and more specifically, work orientation followed by self-reliance and identity, individually contributed to the prediction of school grades. The three parenting style dimensions (warmth, supervision, and psychological autonomy granting) and one parental involvement dimension (affective support) showed a positive relationship with work orientation. Parent-adolescent interactions on daily school matters were negatively related to autonomy and work orientation. Parental warmth had a direct relation, through autonomy and two of its dimensions, on school grades, work orientation, and self-reliance, whereas psychological autonomy granting and affective support had both a direct and an indirect effect. Supervision was found to partially mediate the link between work orientation and school grades. Findings lend support to the importance of considering autonomy and at least two of its dimensions, work orientation and self-reliance, in the study of parenting and parental involvement practices in relation to school grades. (Contains 27 references.) (Author/KB)