The study of high school students motivation has gained remarkable relevance in the pursuit of their well-being and more efficient learning, as a way to address the high truancy rates in this final stage of Brazilian basic education. Several actors can influence the flourishing of individuals, especially the family, which, through its practices, becomes a source of collaboration or disruption to adolescent motivation. This research aimed to investigate the relationships between parenting styles and high school students motivation. To do so, we relied on the theoretical framework of Maccoby and Martin s Parenting Styles and Deci and Ryan s Self-Determination Theory. The work was divided into two stages, using mixed methods. In the first stage, of qualitative assessment, open interviews were performed with 41 students from a federal school in Rio de Janeiro. The objective was to do an initial assessment about students perceptions of the reasons that lead them to study and go to school, in such a way that this exploratory study could contribute to the construction of a motivation scale for high school students. Although it was observed that most of the categories found were interchangeable, specific categories were identified for each question. These data reveal that, despite most motivations being similar, there are motivational particularities that need to be evaluated within their specific context. The second, of quantitative assessment, consisted of applying three psychometric scales to a sample of 818 students from Rio de Janeiro. The first instrument used, called the High School Study Motivation Scale, was developed, throughout this work, based on the results of the first stage. The exploratory factorial analysis employed revealed a threedimensional model, grouping the new structure into 31 items, so that the type of motivation that obtained the highest average per item was controlled, followed by autonomous and demotivation appearing with the lowest average. New adjustments were suggested to refine the structure of the model, as pointed out by the confirmatory factorial analysis. The second scale, Measure of Motivation for Learning in Technical and Vocational Education, was also used to evaluate the motivation of these students, focusing on aspects that motivate students to go to school. The analysis of the avarage by dimensions found that the highest score was identified motivation, while demotivation stood out with the lowest average. The third scale applied was Instrument to Assess Perceived Parental Responsiveness and Demand in Adolescence. It was observed that both maternal and paternal demand and responsiveness dimensions have the potential to influence children s motivation, even though weakly or moderately. Regarding parenting styles, the research found that authoritative mothers and fathers promote more autonomous motivation in their children, authoritarian mothers tend to have children with controlled motivation, and neglectful mothers and fathers usually have demotivated children. From the synthesis of these results, it can be concluded that parenting practices with a higher level of responsiveness and demand are more beneficial for adolescent motivation than practices that have a high level of demand but low responsiveness. The worst practices can be considered those that have a low level for these two dimensions.