This investigation tested the effectiveness of inoculation treatments on 790 participants. The study probed the relationship between threat and involvement, their role in inoculation, and the nature of cognitive processes triggered via inoculation. The pattern of results suggests that inoculation elicits threat, threat contributes to resistance, and resistance is most pronounced for more involved receivers and on behalf of more involving topics. Finally, the results shed additional light on the process of inoculation but revealed a process considerably more intricate than was initially predicted. Structural equation analyses indicated that inoculation and involvement exert parallel, but independent, effects throughout the process of resistance. Both contributed directly to resistance, and both indirectly furthered resistance, but along unique paths. Whereas inoculation elicited receiver threat, which indirectly enhanced resistance through its sizable and immediate impact on Phase 2 attitudes, involvement contributed to the process of counterarguing and, thus, exerted a delayed indirect impact on Phase 3 attitudes.