PURPOSE: The purpose of this study was to identify factors affecting the social competence of school-aged children according alcohol consumption by their parents. METHODS: The participants were 558 5th grade elementary school students. Data were collected using structured questionnaires from September 17 to October 2 2013, and analyzed using descriptive statistics, chi2-test, t-test, ANOVA, Pearson correlation coefficients, and Stepwise multiple regression analysis with the SPSS PC+ 21.0 program. RESULTS: Participants were classified into three groups according to alcohol use; Non-use parent group (52.7%), social use parent group (31.0%), and problem use parent group (16.3%). Participants whose parents were problem users had significantly lower scores on emotional awareness and expression (F=14.45, p<.001), social support (F=5.82, p=.003), and social competence (F=16.33, p<.001) compared to students in the other two groups. In school-aged children with parents who were alcohol abusers, the variables that predicted social competence was friend support (66.0%). CONCLUSION: These results emphasize the importance of focusing on the crucial role of peer support in the development of social competence in school-aged children of parents who abuse alcohol. Further, for these children, interventions aimed at improving social support and children's emotional awareness and expression may be most beneficial.