It is widely acknowledged that physical activity can play a potentially important role in enhancing public health. However, rapid and signi cant decreases in physical activity practice occur during adolescence. Elements such as parents’ perceptions of their children competence, children’s self-perceptions of competence and motivation appear to be important in this process. e main goal of this study was to test the following sequence of motivational processes related to physical activity: Competence Metaperceptions (parents) - Competence Self-Perception – Self-Determined Motivation–Intention to be Physically Active–Physical Activity. 459 adolescents (257 males, 202 females), age range 12-17 years, agreed to participate. Descriptive and exploratory analysis, bivariate correlations and path analysis were performed. e testing of the hypothesized model showed a good t to the data. Results reinforce the influence of parents’ views on their children’s physical activity competence perception, and its consequences on the adolescents’ physical activity.