Based on a resilience perspective, this study attempted to explore the risk and protective factors influencing the mental health of immigrant and local youths in Hong Kong. A structured questionnaire which consisted of The Chinese Adolescents Life Events Checklist, The Perceived Satisfaction of Social Support Scale and The Brief Symptoms Inventory was used. Two hundred and ten local and immigrant youths between the age of 15 and 20 were individually interviewed by the trained interviewers. Contrary to our hypotheses, the findings revealed that immigrant youth had better mental health and similar levels of stress than local youth. Moreover, peer support was found to exert a strong impact on the mental health of immigrant youth. While 'Interpersonal relationship difficulties' was identified as a common risk factor faced by local and immigrant youths, immigrant youth faced additional risk factors in relation to a change to a new school and parental conflicts. On the other hand, endurance of hardship, social competence and peer support were considered as the protective factors that might be associated with better mental health in immigrant youth. The implications of this study included: to adopt a resilience perspective to understand the protective mechanisms that enhance the mental health of immigrant youth; to develop a national strategy to build up the interpersonal relationship skills of youth in a society; and to organize specific programmes to strengthen the peer system and tackle parental conflicts in immigrant youths.