This study investigates the emotional labor of fast fashion sales personnel using the qualitative research method. The research was performed through an in-depth interview with 10 sales personnel (managers, coordinators, head cashiers, and sales associates) who experienced fast fashion brands from July to October in 2011. The results of this study provide that fast fashion brands do have specific feeling rules and display behavior. Even though the sales personnel spend an extremely short time (about 1 minute) to serve customers, most of them experience exhaustion, fatigue, burnout and self-alienation because of emotional dissonance. Sales personnel do deep-acting and surface acting simultaneously and interviewees who have longer and more sales experience express less emotional dissonance. To reduce the negative results of emotional labor, the company plays an important role through the organizational culture; in addition, deep-acting could be recommended for a beginner until they are comfortable with sales. The results of this study provide the elements of emotional labor in a fast fashion and practical suggestions for store operation and sales personnel training.