We draw on a comprehensive database of American political advertising and television audience profile data to investigate the ways in which gender influences choices about the use of voice-overs in political advertising. Our findings suggest that although men voice the vast majority of political ads, campaigns do strategically choose the sex of the voice-over announcer and that it systematically varies with candidate characteristics, ad tone, and, to a lesser extent, issues. Moreover, using survey data, we show that the choice of voice-over influences the perceived credibility of the ad.Modern political campaigns are increasingly sophisticated operations, and little is left to chance. Even minor decisions are made after careful study by experienced campaign professionals. This extends to decisions about political advertising, including what type of content to air, when and where. Indeed, the development of a political ad can be a lengthy process, one that includes message testing with focus groups, in order to get every last detail right (Johnson, 2001). In short, campaigns' choices about the content of their political ads are strategic, especially in well-financed campaigns for federal office.One of the choices that campaigns must make is whether to employ a voice-over announcer, and if so, whether that announcer should be a man or a woman. At first blush, that might seem to be a minor choice, but it is one that many campaigns take seriously-and one that is consequential. We will show that the choice of a man or woman to voice an ad varies systematically with several features of the ad and composition of the ad's intended audience. Moreover, using a wealth of survey data collected during the 2012 presidential campaign, we will show that the sex of the voice-over announcer influences perceptions of an ad's credibility, which is a known antecedent of persuasion