Purpose: This study sought to investigate the relationship between smoking, drinking and the mental health of adolescents. Method: The study subjects included 1,092 randomly sampled third-year middle and high school students from N-City and the L-Kun area in Chonbuk Province. The data were collected using an anonymous questionnaire developed by the Ministry of Health and Welfare(2005). The data were analyzed using the SPSSWIN 15.0 Program. Result: The smoking rate in the adolescents was 10.1%, and the drinking rate was 43.2%. The stress recognition rate in normal daily life was 45.5%, the frequency of depressive symptoms was 33.2% and 40.0% of the subjects reported that they wanted to die at some point within the past year. The rate of stress recognition, depressive symptom experience, suicidal planning and attempt in smokers and drinkers was higher than that in non-smokers and non-drinkers (p<.05). Especially, the frequency of suicidal thoughts was higher in the drinkers than in the non-drinkers (p<.05). Conclusion: The smoking and drinking status of the adolescents was correlated with their mental health a sit relates to stress, depression and suicide. Therefore, an effective program for the prohibition of cigarette smoking and alcohol consumption is needed in order to prevent smoking and alcohol consumption in adolescents and improve their mental health status.