How does gender affect the attack strategies of political actors? Do men and women diverge in their propensity to go negative and in their choice of targets? Extant research has long sought to shed light on these questions (e.g., Brooks 2010; Kahn 1993; Krupnikov and Bauer 2014; Proctor, Schenck-Hamlin, and Haase 1994; Walter 2013). Among all the possible determinants of attack behavior in elections, candidate gender has been one of the most “heavily studied” (Grossmann 2012, 2). However, the relevant research focuses almost exclusively on the United States and therefore on a system with candidate-centered campaigns, weak party organizations, and winner-takes-all competitions. Notwithstanding the importance of the USA as a case and exporter of campaign techniques, such context is specific and likely to bias the results. The few pioneering studies that examine the role of gender in negative campaigning outside the U.S. (Carlson 2001, 2007; Walter 2013) have addressed this question mostly by transferring the analytical framework of U.S.-based research to other political systems. Consequently, they have barely begun to incorporate the distinctive features of multiparty systems and strong party organizations as determinants of gender differences in attack behavior. The present article provides a novel argument about the role of party environments as a crucial context factor in party-centered political systems. Specifically we argue that in party-centered campaigns the gender balance within parties influences differences in the attack behavior of male and female politicians.