This study examines the role ethical salesperson behavior plays in relationship selling. Four key findings emerge from a sample of purchasing agents. First, ethical salesperson behavior is positively related to trust in the salesperson. Second, the effects of ethical salesperson behavior on buyer commitment and buyer behavior are completely mediated by this trust. Third, ethical salesperson behavior is most influential in driving desirable resource-based and social relationship returns, and least influential in driving desirable economic returns. Fourth, the effects of ethical salesperson behavior are moderated by buyer age such that they become significantly stronger as buyer age increases. Managerial and theoretical implications are discussed, and avenues for future research in the area are provided. © 2009 PSE National Educational Foundation. All rights reserved.