Few studies have examined the relationship between interpersonal stress and body image in young adults. The present experimental study tests the effect of peer stress on general and weight-specific state body dissatisfaction, and the moderating role of gender and appearance importance. N = 111 university students aged between 18 and 25 years were randomly assigned to three conditions in which peer stress was elicited through vicarious rejection scenarios based on appearance or personality, or a no rejection control. Results supported a significant but complex peer stress effect on state body dissatisfaction, moderated by gender and appearance importance. Specifically, males in a personality-based peer stress condition reported greater general body dissatisfaction compared to males in appearance-based and no rejection conditions. Further, participants exposed to appearance-based peer stress including those placing low value on appearance - reported greater weight dissatisfaction compared to the no rejection control and personality rejection conditions. Females and participants reporting high appearance importance were shown to report greater body dissatisfaction in general. The results hold implications for prevention and early intervention programs in young adults, and suggest stress management training could target the peer domain in this population. (C) Copyright 2016 Textrum Ltd. All rights reserved.