Self-disclosure on social networking sites was found to be related to cyber victimization, loneliness, and psychological distress. However, few studies have investigated the mediating role of cyber victimization in these relationships among adolescents, especially in Vietnamese adolescents. This paper aims to investigate the indirect effect of cyber victimization on the path from self-disclosure on social networking sites to loneliness and on the path from self-disclosure to psychological distress among Vietnamese adolescents. Responses from 980 Vietnamese adolescents (M[subscript age] = 16.39, SD = 0.592) with no missing data were used for the analysis. The results indicated that: (1) cyber victimization partially mediated the link between self- disclosure and loneliness; and (2) cyber victimization fully mediated the link between self- disclosure and psychological distress. Interventions aimed at reducing the risk of cyber victimization can help reduce loneliness and psychological distress in adolescents who have self-disclosed on social networking sites.