Mental disorder is amongst the most important public health issue that young people are facing in Hong Kong. However, there is so far no population-based data for a comprehensive understanding of the current status of youth mental health. Hong Kong Youth Epidemiological Study of Mental Health (HKYES) is the first psychiatric epidemiological study aiming to examine the prevalence and correlates of mental disorders among young people in Hong Kong. Preliminary results regarding depression in youths will be presented.