This study examines whether, in a male prison, the subjective experience of crowding increases the likelihood that events are perceived as aggressive in nature, and whether the protagonists involved are viewed as more hostile, malevolent, and aggressive. In addition, this paper also examines the possible mediating effects of stress, arousal, and psychological well-being on two hypothesised relationships. First, these mediating factors are examined for the link between individuals' personal space preferences and their perceived level of crowding. Second, these factors are examined for the link between perceived crowding and interpretations of an aggressive event. Such associations may help to explain why crowding and aggression are linked within a social interactionist perspective. The results confirmed previous findings that crowding is linked to increases in arousal and stress, and a reduction in psychological well-being. This study also found, however, that those inmates who experienced crowding were also more likely to interpret behaviour as aggressive and violent. This relationship was not mediated by arousal, stress, or psychological well-being. However, these factors were found to partially operate in the relationship between personal space preferences and the experience of subjective crowding. The implications of this study for social interactionist explanations of the link between crowding and prison violence are offered.