Anxiety is believed to have evolved, in part, as a signal of threats to survival or reproductive fitness. In a sample of 66 heterosexual undergraduate men who were currently in exclusive romantic relationships, we explored whether symptoms of anxiety mediated links between anticipated partner infidelity and men's intimate partner violence. Results indicated that symptoms of anxiety mediated relationships between anticipated partner infidelity and physical aggression, partner injury, psychological aggression, and sexual aggression toward a partner. Results are discussed in terms of the evolution of anxiety as an emotion that mediates reaction to adaptive threats.