The aim of this study was to assess whether exposure to urban pollution in outdoor workers, may alter plasma cortisol concentrations also in relation to the effect of smoking and drinking habits. The research was carried out on 498 outdoor police workers, divided into three groups; Group A: traffic policemen (TP), Group B: drivers (D), Group C: Other duties (OD). To evaluate separately the effect of using alcohol and smoking, each group was divided into three subgroups: (1) non-smokers and non-drinkers, (2) smokers and non-drinkers, (3) non-smokers and drinkers. Our results show cortisol mean values were significantly higher in the TP group compared to the D and OD groups without significant differences between the last two groups. The results suggest that exposure to pollutants associated with urban psychosocial stress may play a more important role on plasma cortisol levels than smoking and alcohol.