OBJECTIVE: To investigate the prevalence and correlates of bullying and victimization behaviors in boys and girls at South Korean primary schools. METHOD: In a cross-sectional survey, 1,344 fourth-grade primary school children completed a questionnaire on self-reported bullying and victimization behaviors, depression, anxiety, body image, coping strategies, and self-esteem as well as the self-report Strengths and Difficulties Questionnaire. Parents completed a questionnaire on demographic data, the General Health Questionnaire-12, and the Korean version of the Strengths and Difficulties Questionnaire. RESULTS: The prevalence of bullies, victims, and bullies/victims was 12.0%, 5.3%, and 7.2%, respectively. Boys were significantly more likely to be bullies and bullies/victims. In the multivariate analyses, bullying and victimization behaviors were associated with gender, greater than average height, higher depression, higher trait anxiety, lower self-esteem, and total difficulties of the Strengths and Difficulties Questionnaire. Differences in the associations were found between boys and girls. CONCLUSIONS: The authors found that bullying is common among South Korean primary school students and that bullying and victimization behaviors are related to various emotional, behavioral, and social problems; some gender-related differences are also evident.