Introduction: Smoking is one of the types of social harms among students. Most review studies have reported the prevalence of smoking in its various forms and have less focused on the factors affecting smoking among students. The aim of the present study is to systematically review related research and conduct a meta-analysis of the most important factors affecting smoking among Iranian students.

Method: National and international databases such as Magiran, IranMedX, Google Scholar, Scopus, PubMed, etc. were searched in the period 1370-1404, and finally 18 scientific documents whose quality was confirmed based on the Strobe checklist were analyzed using comprehensive meta-analysis software.

Results: Analysis of the results of the combination of effect sizes shows that the variables of best and closest friend who smokes, presence of a friend who smokes, and presence of a smoker in the family, respectively, with combined effect sizes of 0.985, 0.952, and 0.879, had a high level of effect on their smoking rate. Also, the variables of general risky behavior (0.489), lack of religious beliefs (0.456), tendency to smoke (0.422), and students' self-confidence (0.359) had a moderate level, and other variables such as students' age (0.238), gender (0.201), and finally academic failure (0.187) had a low level of effect on the dependent variable, which is smoking among students.

Conclusion: Given the importance and sensitivity of adolescence, there is a special need to establish policies and programs to prevent smoking, especially among students. The aforementioned policies should be action-oriented and based on the discussion of prevention.