Given the prevalence of brand extensions in the market, it is important to consider extensions' potentially harmful effects on the parent brand, that is, negative feedback effects. This paper integrates experimental research on negative feedback effects using a meta-analytic framework. The results support previous findings for extension evaluations, parent brand breadth, parent brand image fit, and consumer task motivation on the occurrence of negative feedback effects. However, four moderator variables found in earlier work are not significant: accessibility of extension information, parent brand awareness, branding strategy, and participant type. Mixed findings related to extension fit, valence of extension information, and parent brand quality are clarified, indicating that extension fit and valence of information appear to drive negative feedback while parent brand quality does not. Four methodological factors have significant effects: within-subject-dependent variable designs, parent brand product class, type of brand, and whether the extension was evaluated, suggesting that the effects may be, in part, an artifact of background factors. The results provide insights into when brands seem vulnerable to negative feedback effects, while simultaneously identifying common market scenarios under which brands appear less susceptible. Finally, a post hoc model points to involvement and level of processing as two key constructs that may underlie the effects of moderators.