Air pollution is becoming a serious socio-environmental problem in many modern societies and poses significant economic threats to popular tourism destinations. Despite the documented consequences of air pollution on tourism demand, studies have seldom examined its impact on individuals’ psychological states, especially in the tourism context. Through a correlational study and two experiments, our findings indicate that tourists are more likely to be suspicious of local service providers when travelers perceive a destination as having heavy air pollution (vs. one without such pollution). This relationship presumably exists because tourists experience greater pessimism in an environment with high air pollution, which in turn influences their evaluations of service providers. Following this logic, we show that the effect diminishes when tourists are cognizant of (and thus rely less on) their pessimistic feelings when evaluating service providers. Finally, we offer theoretical and practical implications of this effect in tourism.