While environmental corporate social responsibility (CSR) has gained increased attention in sustainable tourism research, little is known about its impacts on customers in the context of the airlines. This study investigates the impact of environmental CSR on two critical customer outcomes, namely, purchase intention (PI) and switching behavior (SB). In light of the stimulus–organism–response (S-O-R) framework, this study further examines the joint mediating impact of customer equity drivers (CEDs) in the previously mentioned relationships. With a sample of Iranian air travelers, the results of the structural equation model revealed that environmental CSR significantly affects CEDs. While CEDs predict PI, they failed to reduce SB. Hence, CEDs jointly mediate the impact of environmental CSR on PI only. The results of the current study reveal nuances in the service marketing research by extending the impact of environmental CSR on travelers’ PI and SB via CEDs. Theoretical and practical implications are provided.