DescriptionResearch on body shame has predominantly focused on women (Moradi & Huang, 2008). However, men are increasingly viewing muscularity as an important feature of masculinity (Kimmel & Mahalik, 2004; Wienke, 1998). My dissertation reviews the literature on male body image and its connection to masculinity; establishes how body shame may constitute a chronic masculinity threat and explores how and why men may react to acute masculinity threats with sexual aggression. Findings from prior research suggest that men high on body shame are more likely to sexually aggress (Mescher & Rudman, 2014) – a unique finding which has implications for rape theories and precarious manhood theory (Vandello, Bosson, Cohen, Burnaford, & Weaver, 2008). This dissertation tested the Body Shame and Sexual Aggression Model (BSSAM) in two experiments. Experiment 1 manipulated men’s exposure to idealized body media to test proposed relationships between media consumption, body dissatisfaction, body shame and upward social comparison, and found support for the path from body dissatisfaction to body shame, regardless of media exposure or comparison. Experiment 2 was designed to replicate and extend results from Mescher and Rudman (2014), in which men high on body shame responded to a female confederate’s rejection of them as a dating partner with increased sexual aggression; previous findings did not replicate, but it is speculated that this may be partially due to the inclusion of a novel measure of men’s beliefs about having been romantically victimized by women. The pilot test designed to validate this measure is also discussed.