The main aim of the present study is to investigate the indirect effect of the association between thin-ideal internalisation (1), muscular-ideal internalization (2) and body dissatisfaction (BD) through the general social appearance comparison separately among boys and girls. 154 adolescents (mean age 18.2 years, SD = 0.73; 56.5% girls) provided information on the explored variables. Two hierarchical regression models were carried out for boys and girls separately. The general appearance comparison works as an important explanatory mechanism in the relationship between thin-ideal internalization and BD among girls as well as between muscular-ideal internalization and BD among both boys and girls. The more individuals internalize the societal ideals of appearance, the more they compare their physical appearance to others and thus the greater BD they perceive. The current results contribute to previous research findings by indicating the social appearance comparison as a risk factor which enhances BD among both boys and girls in late adolescence. The findings may facilitate identifying individuals who are vulnerable to body dissatisfaction earlier, before more serious eating problems occur.