The emotion of disgust has been claimed to affect a diverse array of social judgments, including moral condemnation, inter-group prejudice, political ideology, and much more. We attempt to make sense of this large and varied literature by reviewing the theory and research on how and why disgust influences these judgments. We first describe two very different perspectives adopted by researchers on why disgust should affect social judgment. The first is the pathogenavoidance account, which sees the relationship between disgust and judgment as resulting from disgust's evolved function as a pathogen-avoidance mechanism. The second is the extended disgust account, which posits that disgust functions much more broadly to address a range of other threats and challenges. We then review the empirical evidence to assess how well it supports each of these perspectives, arguing that there is more support for the pathogenavoidance account than the extended account. We conclude with some testable empirical predictions that can better distinguish between these two perspectives.