Objective: One of the main concerns of health–social policymakers in nowadays societies is the increasing prevalence of addictive behaviors, particularly cigarette smoking and smoking in younger age groups. This study aimed to compare the attachment style, perceived loneliness and mental health between smokers and non-smokers of dormitory students.Method: using the ex-post facto design for studying all Shahid Beheshti University students in the 91-92 school years. The sample consisted of 50 smokers and 50 nonsmokers, which selected by convenient sampling. And the demographic questionnaires of attachment style, perceived loneliness and mental health answered. Multivariate analysis of variance (MANOVA) was used for data analysis.Results: findings of study showed, there are significant difference between smokers and non-smokers students in attachment style, perceived loneliness and mental health scales and. People who have smoked had more insecure attachment style, loneliness feeling and less mental health.Conclusion: The results of the present study indicate that smoking is influenced by personal factors, and attachment style, loneliness feeling and mental health are associated with smoking.