Numerous situational factors are known to increase the likelihood that a person will behave aggressively. The current review addresses what is currently understood about the relationship between three theoretically relevant situational variables (the presence of weapons, alcohol cues, and exposure to media violence) and aggressive behavior. Theoretical models of aggression generally propose heightened accessibility of aggressive cognitions (i.e., priming) as a common mechanism to explain effects of these variables on aggression but differ in terms of factors that modulate whether and how activated mental content will influence behavior. Here, we discuss these factors and suggest ways in which models of priming might be integrated. We also underscore that, although aggression has been the focus of considerable research for decades, much more research is needed to better understand the psychological and biological processes that mediate effects of situational cues on aggression in humans.