Objectives: This study aims to examine the association of depression, suicidal behaviors with smartphone use behaviors among Koreanadolescents. Methods: We analyzed data from ‘Youth Health and Life Skills Survey’ in 2013. The survey was based on self-reportedquestionnaires distributed to 915 grade 7th and 8th students at four middle schools in Gangdong-gu, Seoul, Korea in 2013 to evaluate theeffects of 'Youth Health and Life Skills' program. Depression and suicidal behaviors were measured in terms of the experience rate, andsmartphone use behaviors were measured with average hours of smartphone use a day and overindulged behaviors in smartphone use byusing 5-point Likert scales. We examined the association of depression and suicidal behaviors with smartphone use behaviors by using t-testand regression analyses. Results: 21.5% of respondents have ever felt depressed or hopeless to lose interest in school life almost everydayfor 2 weeks or longer in the past year. The experience rate of suicidal ideation, suicide plan, and suicidal attempt were 21.1%, 6.1%, and5.7%, respectively. The mean of average hours of smartphone use a day was 3.9 hours, and the mean score of overindulged behaviors insmartphone use was 2.99. The students who have experienced depression and suicidal behaviors were more likely to have more smartphoneusing time and higher scores of overindulged behaviors in smartphne use than those who have not. Conclusion: We concluded that forpreventing addictive or problematic smartphone use behaviors among adolescents we should consider and develop more positive strategiesfor the moderate use of smartphone than regulatory measures, which include the implementation of skill-based health education programincluding life skills at schools and the development of smartphone applications useful for resolving mental stress and promoting mental health.