Four studies investigated a self-control theory of resistance to persuasion. This theory asserts that resistance to persuasion requires and consumes self-control resources. Study 1 showed that resistance to a persuasive message reduced the ability to engage in a subsequent self-control task. Studies 2 and 3 showed that self-control depletion leads to increased persuasion. Study 4 showed that self-control depletion increased persuasion, particularly under effortful resistance (i.e., strong arguments). Together, these findings suggest that self-control plays a vital role in the process of resistance to persuasion. People must have self-control resources to fend off persuasive appeals; without them, they become susceptible to influence.