Empirical research into the possible positive consequences of deliberation increasingly reveals that there is a complex relationship between deliberation and its effects on citizens. In this experimental study I examine the relationship between internal political efficacy and one type of deliberation: deliberative decision-making. I also test whether different structures of decision-making mediate between deliberation and internal political efficacy. The data suggest that deliberative decision-making had no direct effect on a global measure of internal political efficacy. Participants in face-to-face deliberative decision-making, though, had higher scores on a situation-specific measure of internal political efficacy than participants who only voted. The structures of decision-making had no effect on either measure of internal political efficacy. These results support claims that deliberation will not necessarily lead to direct, positive effects on citizens’ internal political efficacy, but they also highlight the likelihood that face-to-face deliberation can lead citizens to feel more competent in their deliberative abilities.