Few empirical studies have examined adolescent mental health in Central Asia, and data from Uzbekistan are especially scarce. This study aims to assess the prevalence of stress, anxiety, and depression among adolescents and to investigate the impact of school climate on their mental health. This research employed a quantitative survey approach. A total of 22,854 adolescents aged 12-18 across 299 schools in urban and rural areas of Uzbekistan were surveyed. The findings indicate that a considerable proportion of students showed elevated levels of stress (16%), anxiety (22%), and depression (18%), which is consistent with similar studies in other countries. Moderate negative correlations were observed between these levels and perceptions and attitudes towards teachers, peers, social connectedness, and exam perceptions. In the context of ongoing reforms in Uzbekistan, the findings provide an empirical baseline for designing school-based interventions and offer a broader understanding of adolescents’ mental health in non-Western contexts.