Purpose: The aim of this study was to identify the influence of knowledge, attitude and preventive health behavior of cancer on nicotine dependency in male college students who have a habit of smoking. Methods: In this study, a cross-sectional survey design was adopted for the 254 male college students who smoke in D and S city. The data was analyzed for descriptive statistics, t-test, Pearson’s correlation coefficient and multiple regression analysis using the SPSS 20.0 program. Results: Knowledge about lung cancer (β=-.407, p<.001), preventive health behaviors about cancer (β=-.223, p<.001) and the smoking period (5years≤) (β=.198, p=.001) were identified as the factors influencing nicotine dependency of the subjects. The model explained 33% of variance in nicotine dependency (F=20.49, p<.001). Conclusion: The results suggest that anti-smoking educators should include the strategies to increase knowledge about lung cancer and preventive health behaviors of cancer, and to reduce the smoking period in their smoking cessation program.