ObjectiveAlthough heated tobacco products (HTPs) have become popular worldwide, research on occupational differences in smoking HTPs remains scarce. We aimed to examine the prevalence of smoking HTPs among a working population in Japan.Setting, design and participantsIn 2018, we conducted a cross-sectional study comprised of 7714 retail business workers in the service industry in Japan.Primary and secondary outcome measuresFor the definition of smoking HTPs, we identified current HTP smokers who only smoked HTPs, using five mutual categories of current smoking status (never, former, HTPs only, combustible cigarettes only and dual smokers who smoked both combustible cigarettes and HTPs). Occupational classes were classified into office workers (eg, upper non-manual workers) and other workers. ORs and 95% CIs of office workers were estimated for HTP usage, adjusted for age, sex, employment type and cigarette smoking-related health knowledge.ResultsThe overall prevalence of smoking HTPs was 3.0% (male 5.0%, female 2.2%). The prevalence of HTP smokers differed across occupational classes (5.6% in office workers vs 2.5% in others; p<0.05). Compared with other workers, the adjusted odds of office workers for smoking HTPs remained elevated (OR: 1.97, 95% CI: 1.40 to 2.77). Sensitivity analyses with workers of all smoking status showed the same pattern. When stratified by sex, the occupational difference only remained significant in male workers.ConclusionsWe found a positive occupational difference in smoking HTPs, particularly among male workers in the retail sector in Japan. National tobacco control should explicitly address this occupational gap and further encourage individuals to quit smoking.