Selective exposure refers to the tendency of individuals to attend to information that is in line with their political views. This study advocates a behavioral approach to selective exposure research by introducing eye-tracking as a straightforward measure of selection processes. We tested participants' selective exposure to political poster advertisements from one left-wing and one right-wing party. Individuals were simultaneously exposed to on-screen ads by the two different parties, and their eye movements were unobtrusively recorded. Findings indicate that the political orientation of the participants explained selective exposure in terms of the time taken to look at each ad. Implications for selective exposure research are discussed.