ObjectiveThe identification of susceptible non-smoking adolescents is an essential step in reducing smoking initiation among adolescents. The aim of this study was to examine the prevalence and factors associated with smoking susceptibility among non-smoking school-going adolescents in Malaysia.DesignCross-sectional study.SettingPrimary and secondary schools in Malaysia.Participants11 246 non-smoking school-going adolescents.Outcome measuresThe prevalence and factors associated with smoking susceptibility among non-smoking school-going adolescents in Malaysia.ResultsApproximately 14% of non-smokers were susceptible to smoking, and the prevalence of susceptibility was significantly higher among males, ever-smokers and e-cigarette users. The odds of susceptibility to smoking were higher among males, e-cigarette users, those aged 12 years and under and those who had ever smoked or tried cigarettes. Students from schools with educational programmes on the health effects of second-hand smoke (SHS) and who perceived smoking to be harmful were less likely to be susceptible to smoking.ConclusionSmoking susceptibility is prevalent among school-going adolescents. A comprehensive approach that enhances or reinforces health education programmes on the adverse health effects of smoking and SHS among school children, that considers multiple factors and that involves all stakeholders is urgently needed to reduce the prevalence of smoking susceptibility among vulnerable subgroups, as identified from the present findings.