Besides endangering human health, air pollution has profound effects on individuals’ cognition, emotions, and behavior. Previous studies have found that air pollution could increase self-oriented lies. We summarized two explanations for this phenomenon: (1) air pollution makes people less likely to regard lies as unethical, and (2) air pollution makes people more likely to approach materials rewards. The present study mainly measured three kinds of lies—self-convenience, other-convenience, and other-material lies—to investigate these two explanations. Participants were asked to imagine living in either a polluted or a clean situation in two online studies and one laboratory study. The results showed that air pollution did not influence self-convenience lies (Studies 1 and 2), and clean air increased both other-convenience and other-material lies (Studies 2 and 3). According to these results, both explanations are supported. The theoretical implications of the present study are discussed.