Repetitive negative thoughts are generally viewed as a specific cognitive vulnerability factor that seems to be involved in the etiology and maintenance of emotional problems. The existing study aimed to investigate the role of repetitive negative thoughts in the vulnerability for emotional problems and determine the prevalence rates of this problems among secondary schools' adolescents, hence, a descriptive cross sectional study design was used. A self- administered questionnaire sheet was used to collect data from 480secondary schools' student. Study results revealed that there were significant positive correlation between neuroticism as an indicator of general vulnerability, repetitive negative thoughts and emotional problems. Whereas, behavioral inhibition had a significant negative correlation with repetitive negative thoughts and emotional problems. Further, more than three quarter (77.6%) of the studied students have symptoms of depression and majority (87.3%) of the studied students have symptoms of anxiety. Conclusion, depression and anxiety had high prevalence rates among adolescents. also, repetitive negative thoughts contribute to adolescents' vulnerability for depression and anxiety. Consequently it is recommended to Conduct school and community-based mental health promotion and prevention programmes directed toward adolescents, their families, educational staff and others who have direct contact with adolescents. And consider repetitive negative thoughts clinically can be effective in treatment of depression and anxiety.