Resumo. ABSTRACT The objective of this research was to analyze the effect of level of physical activity on perception of mood states among young students in the final grades of high school. The sample consisted of a total of 216 students, of both sexes, with an average age of 16.89±1.48 years. This cross-sectional research was characterized as descriptive and of a quantitative nature. For data collection, the Brunel Mood Scale (BRUMS) and the Habitual Physical Activity Questionnaire were used. Normality was verified through the Kolmogorov-Smirnov test. Subsequently, inferential statistics for non-parametric data were applied, with the Kruskal-Wallis and Dunn’s Post-Hoc tests. Spearman’s correlation coefficient was used to check the relationship between level of physical activity and mood states. Significance was set at p<0.05. From the results, we found that the perception of mood states reported by young students had significant differences when we consider this population’s level of physical activity. Young individuals classified as physically inactive reported a lower level of vigor, as well as a greater predisposition to negative mood aspects compared to physically active ones. In this case, physical activity can contribute to a better perception of psychological health.