Purpose: This study was aimed at evaluating the effects of a smoking cessations health camp on levels of expiratory Carbon Monoxide concentration, self-efficacy, smoking knowledge and nicotine dependence among adolescents smokers. Methods: This research uitlized a one group pre-test post-test design. The smoking cessations health camp was developed after considering cognitive and behavioral aspects and was provided for two days and one night. The number of subjects was 31 high school students. Data were analyzed using descriptive analysis and paired t-test. Results: As compared to a pre-test, the average score of expiratory CO concentration and nicotine dependence were significantly lower and the average score of smoking knowledge was significantly higher in a post-test. An increase in the mean score of self-efficacy was not statistically significant. Conclusion: These results suggest that this smoking cessations health camp can provide teen smokers with the insightful antismoking information and an opportunity for anti-smoking practices. Therefore, this smoking cessations health camp can be effective and useful for adolescent smokers in other school settings.