The current study explored body image self-discrepancy as moderator and social comparison as mediator in the effects on women from thin-ideal images in the media. Female undergraduates (N = 112) with high and low body image self-discrepancy were exposed to advertisements either with thin women (thin ideal) or without thin women (neutral-advertisement control). Exposure to thin-ideal advertisements increased body dissatisfaction, negative mood, and levels of depression and lowered self-esteem. In addition, social comparison processes mediated the relationship between exposure to thin-ideal advertisements and negative self-directed effects. Notably, self-discrepancy moderated this mediation. Women with high levels of body image self-discrepancy were more likely to engage in social comparison from exposure to thin-ideal advertisements, as well as more likely to have those comparison processes induce self-directed negative consequences. This research provides support for an individual difference variable (body image self-discrepancy) that moderates the mediating effect of social comparison from exposure to thin-ideal media.