This experimental study examined the effect of skin-based appearance compliments on cognitive performance as well as its moderator and mediator. Participants were 213 adolescent girls (M = 14.24, SD = 0.45) who were randomly assigned to one of the three experimental conditions: (a) appearance compliment, (b) character compliment, and (c) no compliment conditions. The appearance compliment group, compared with the other groups, showed higher levels of state self-objectification and poorer cognitive performance in a Stroop task after receiving positive feedback on their skin tone. Individual differences in appearance contingent self-worth exacerbated the effects of appearance compliment. The conditional indirect effect of appearance compliment on cognitive performance occurred via an increase in state self-objectification. These findings suggest that skin tone is a concern of body image for Chinese adolescent girls, particularly among those who stake their self-worth on physical appearance. We have also provided direct evidence for the mediating role of state self-objectification in the adverse impact of appearance compliment on cognitive performance.