Among the most well-documented and long-standing gender gaps in political behavior are those relating to political ambition, as men have consistently been shown to express a significantly higher level of political ambition than women. Although this gap is well established, the reasons for the differences between men and women remain largely unknown. One possible explanation is that negative stereotypes about women's political ability are responsible. Stereotype threat, as it is referred to in the psychology literature, is a phenomenon where individuals of a social group suffer cognitive burdens and anxiety after being exposed to negative stereotypes that relate to their identity. These disruptions have been shown to alter attitudes and behavior. In order to test this possibility, we employed an experimental design whereby we randomly assigned 501 undergraduate students into threat and nonthreat conditions. While men exhibited higher levels of political ambition in both conditions, women in the nonthreat condition expressed significantly higher levels of political ambition than those women who were exposed to negative stereotypes. The results of this study therefore suggest that the gender gap in political ambition may be partly explained by negative stereotypes about women in politics.