The purpose of this study was to investigate the effect of congruency of parent brand image with self-image, perceived risk, and product knowledge on the attitude towards extended product in fashion brand extension. A survey questionnaire was used to collect data from 170 female college students and collected data were subjected to descriptive analysis and regression analysis using SPSS Window program. The results of this study showed that the congruency of parent brand image with self-image and perceived risk had a positive effect on attitude towards extended product, whereas product knowledge had a negative effect on attitude towards extended product in fashion brand extension. Also, the congruency of parent brand image with self-image had a positive effect on the attitude towards extended product in fashion brand extension with positive moderating effect of perceived risk and negative mediating effect of product knowledge.