OBJECTIVE To examine the extent to which the justice of decision-making procedures and interpersonal relationships is associated with smoking. METHODS 10 municipalities and 21 hospitals in Finland. METHODS Cross-sectional data derived from the Finnish Public Sector Study were analysed with logistic regression analysis models with generalised estimating equations. Analyses of smoking status were based on data provided by 34,021 employees. Separate models for heavy smoking (> or = 20 cigarettes/day) were calculated for 6295 current smokers. RESULTS After adjustment for age, education, socioeconomic position, marital status, job contract and negative affectivity, smokers who reported low procedural justice were about 1.4 times more likely to smoke > or = 20 cigarettes/day compared with their counterparts who reported high levels of justice. In a similar way, after adjustments, low levels of justice in interpersonal treatment was significantly associated with an increased prevalence of heavy smoking (OR 1.35, 95% CI 1.03 to 1.77 for men and OR 1.41, 95% CI 1.09 to 1.83 for women). Further adjustment for job strain and effort-reward imbalance had little effect on these results. No associations were observed between justice components and smoking status or ex-smoking. CONCLUSIONS The extent to which employees are treated with justice in the workplace seems to be associated with smoking intensity independently of established stressors at work.