INTRODUCTION Smoking among boys has not been prioritised as a gender issue despite its high prevalence worldwide. In Indonesia, steep increases in prevalence have been observed in adolescent boys. This study explored how smoking-related beliefs are associated with smoking among this group.METHODS Data extracted from the Global Youth Tobacco Survey Indonesia 2014, provided a nationally representative sample of 2729 male students aged 12-16 years. Measures of smoking-related beliefs were derived from eight survey items using principal component analysis. Associations between resulting components and smoking outcomes were modelled using logistic regression.RESULTS Smoking prevalence was found to be almost tripling between ages 12 to 16 years. Smoking-related belief items clustered into two components: perceived social benefits and perceived harms. The four beliefs representing smoking's perceived social benefits and measures of smokers in the boys' social circles increased with age while the four beliefs representing smoking's perceived harms remained stable except an item of safe to smoke for one or two years, which increased with age. The two components of smoking-related beliefs were associated with smoking in opposite ways that represent boys' masculine tendency for risk-taking and risk minimisation. For example, score increases for perceived benefits were positively associated with susceptibility to future tobacco use (OR=1.6; 95% CI: 1.3-1.9) but an increased score of perceived harm was negatively associated with susceptibility to future tobacco use (OR=0.8; 95% CI: 0.7-0.9).CONCLUSIONS Indonesian boys experience a rapid increase in smoking outcomes and smoking reported among their social circle. The sustained high percentage of smoking harms but also increased social benefits are similar to the concept of risk minimisation that is closely related to the masculine tendency to undermine health hazards of tobacco. Therefore, it is important to focus on these highly gender-related issues within the country.