In two experiments, we examined the hypothesis that subjective perceptions of message quality mediate the functional matching effect in persuasion. In Experiment 1, participants whose attitudes and behaviors serve primarily a value-expressive function (i.e., low self-monitors) or a social-adjustive function (i.e., high self-monitors) were exposed to persuasive messages that contained value-expressive, social-adjustive, or both types of arguments in favor of voting. Functionally-relevant messages (i.e., the social-adjustive message for high self-monitors and the value-expressive message for low self-monitors) produced enhanced perceptions of message quality and persuasiveness, more positive attitudes, and more message-related behavior than functionally nonrelevant messages. Functionally mixed messages were generally more effective than messages containing only functionally nonrelevant arguments, but less effective than messages containing only functionally relevant arguments. Path analyses indicated that the influence of functional relevance on attitudes and behavior was significantly mediated by subjective perceptions of the quality of the message. In Experiment 2, we exposed participants to a functionally relevant or nonrelevant voting appeal five days before a presidential election. Results replicated those of Experiment 1; functionally relevant messages produced more favorable attitudes, and this effect was mediated by enhanced perceptions of message quality. Finally, postmessage attitudes exerted a significant influence on whether participants voted in the election, and this effect was mediated by voting intentions. Discussion focuses on the subjective nature of message evaluation and on the cognitive processes underlying the functional matching effect in persuasion.