Adolescence may bring some developmental challenges that affect social-emotional health. However, it is also possible to turn challenges into opportunities. Parental autonomy support, psychological stress, and mental toughness can contribute to adolescents having a healthy period. This study examined the mediating role of positive stress and mental toughness in the relationship between parental autonomy support and social-emotional health. The study included 441 (female 56.46%, male 43.54%) adolescents in Turkey enrolled in a high school. Self-report scales were used in this cross-sectional study. The results showed that positive stress and mental toughness were serial mediators of the relationship between adolescents' perceptions of parental autonomy support and social-emotional health outcomes (indirect effect = 0.05 [0.03, 0.08]). These results extend the implications of self-determination and positive psychology theories. It guides parents, educators, and school counselors in strengthening adolescents' social-emotional health. Adolescents' socio-emotional health can be enhanced through workshops and counseling services that offer parental autonomy support, positive management of stress, and mental toughness.