This study examines the role of personalized charity advertising in promoting empathy, attitude change, and helping intentions toward stigmatized social groups. Based on theories of message involvement, empathy, and reactance, we predicted that higher levels of involvement elicited by a personalized charity advertisement would reinforce empathy and prosocial outcomes. An online experiment was conducted using a personalized and a nonpersonalized version of a charity advertisement for a campaign soliciting donations of winter coats for homeless people. As expected, structural equation modeling revealed a positive indirect effect of personalization on prosocial outcomes (attitudes and behavioural intentions toward homeless people, and willingness to donate to the campaign) that was mediated by involvement and empathy. However, in addition to promoting involvement and empathy, personalization also led to heightened reactance, which detracted from the positive effects. Theoretical as well as practical implications of the findings for personalized charity advertising are discussed.