We assessed religious volunteers’ intergroup contact, realistic threat perceptions, symbolic threat perceptions, intergroup anxiety, negative stereotypes and prejudice toward Mexicans before and approximately 4–6 months into their volunteer service. Whether assigned to serve Mexicans or European–Americans, all volunteers experienced reduced prejudice toward Mexicans. A multiple mediator model suggests that changes in prejudice resulted from a mediated relationship between quality contact and prejudice. Specifically, intergroup anxiety and negative stereotypes mediated the relationship. The benefits of volunteerism as a means of fostering favorable intergroup contact and reducing threat perceptions and prejudice are discussed. Copyright © 2013 John Wiley & Sons, Ltd.