The end of this study was to determine the relationship between physical activity and sleep quality, depression, anxiety, stress and mental well-being among teenagers. This study was a descriptive survey in terms of practical purpose and in terms of the nature of the subject and goals. The participants of the current research were 407 female students of the first and second year of high school in Ardal city, who were selected as sample. Four standard questionnaires for adolescent physical activity, Pittsburgh sleep quality, depression, anxiety and stress questionnaire and mental well-being questionnaire were the tools of this research. Research data were analyzed using Pearson's correlation coefficient, hierarchical regression analysis. Findings showed that by controlling demographic variables, there is a significant relationship between physical activity and sleep quality, depression, anxiety, stress and mental well-being of adolescents. The results of the research show that physical activity improves the quality of sleep and mental well-being of adolescents, and physical activity has an inverse relationship with depression, anxiety, and stress, and increasing the amount of physical activity is associated with decreasing the level of depression, anxiety, and stress in adolescents.