The purpose of this study is to identify the antecedents of repurchase intention toward fast fashion brands. Perceived quality, perceived price, deindividuation, and overly trendy styles, which are product characteristic variables, and fashion innovativeness, which is a consumer characteristic variable, were considered as antecedents. It was hypothesized that product and consumer characteristics influence repurchase intention toward fast fashion brands not only directly, but also indirectly through cognitive dissonance. Data were gathered by surveying university students in Seoul using convenience sampling. Three hundred and fifty-two questionnaires were used in the statistical analysis. SPSS was used for exploratory factor analysis, and AMOS was used for confirmatory factor analysis and path analysis. The factor analysis of product characteristics revealed four dimensions: “perceived quality”, “perceived price”, “deindividuation”, and “overly trendy styles”, and the factor analysis of consumer characteristics revealed one dimension. The factor analysis of cognitive dissonance revealed two dimensions, “regrets” and “perceived uncertainty.” The hypothesized path test proved that perceived quality, deindividuation, overly trendy styles, and fashion innovativeness influence repurchase intention directly. Perceived price and deindividuation influence repurchase intention indirectly through the factor of cognitive dissonance, which is the perceived uncertainty, indicating the importance of cognitive dissonance. The results indicate effective marketing strategies should be used to decrease consumers’ cognitive dissonance, and suggestions for future study are provided.