Objectives: The purpose of this study is to analyze the relationship between dual smoking and mental health. Methods: This study was conducted on 5,879 Korean adults, and a logistic regression analysis was conducted to investigate the relationship between smoking type and mental health. Results: The types of smoking were surveyed as ‘dual smoking’ 6.1%, ‘electronic cigarette’ 1.7%, ‘general smoking’ 12.1%, and ‘non-smoking’ 80.1%.. The risk of diagnosing depression in the dual smoking group was 2.87 times higher than in the non-smoking group, the risk of depression was 1.66 times higher than in the non-smoking group, and the risk of stress was 1.62 times higher. Conclusion: Even in adulthood, health education such as smoking prevention education and smoking cessation education should be conducted.