AIMS: This study reports on research to determine the prevalence rates and severity of depression, anxiety and stress among Saudi adolescent boys. A cross-sectional study, of secondary school boys at Abha, Aseer Region, Saudi Arabia was conducted. METHODS: The systematic sampling method was used to select a class at each level in a school. All the students were informed in detail about the study. The Arabic version of Depression, Anxiety and Stress Scale (DASS) was used to establish school-boy levels of depression, anxiety and stress. RESULTS: Results indicated that of 1723 male students recruited to this study, 59.4% had at least one of the three disorders, 40.7% had at least two and 22.6% had all the three disorders. Moreover, more than one third of the participants (38.2%) had depression, while 48.9% had anxiety and 35.5% had stress. Depression, anxiety and stress were strongly, positively, and significantly correlated. CONCLUSION: It was concluded that there is an urgent need to pay more attention to the mental health of adolescent secondary school boys in Saudi ArabiFurther studies are needed to explore knowledge and attitude of students, parents and teachers concerning mental health.