Research on ego-depletion suggests that the ability to self-regulate one’s behavior is limited: Exerting self-control on an initial task reduces performance on a subsequent task that also requires self-control. Two experiments tested whether forming implementation intentions could prevent ego-depletion and/or offset the effects of ego-depletion. Experiment 1 found that participants who formed implementation intentions during an initial ego-depleting task subsequently showed greater persistence on an unsolvable puzzles task compared to participants who did not form implementation intentions. Experiment 2 found that among participants who had been ego-depleted during an initial task, forming implementation intentions improved subsequent performance on a Stroop task to the level exhibited by non-depleted controls. Thus, implementation intentions help to enhance people’s ability to self-regulate their behavior.