Children who have been sexually abused may experience various short- and long-term psychological sequelae and behavioral problems. This study assessed the mental health of sexually abused children using the Korean-Child Behavior Checklist (K-CBCL) and examined differences from a control group. The participants were 97 children who had been sexually abused and who visited a local Sunflower Center, and 178 control participants. Data were collected via the K-CBCL and analyzed using SPSS version 25.0. T-tests, cross-tabulation, and logistic regression analyses were performed. Scores from the K-CBCL Problem Behavior Syndrome scale were compared between sexually abused children and the control participants. Significant differences were observed between the 2 groups in all the subscales. Compared to the control group, children who were sexually abused showed statistically significant differences in the total problem behavior, internalization, anxiety/depression, withdrawal/depression (withdrawn), somatic symptoms, externalization, rule-breaking behavior (delinquency), aggressive behavior, social immaturity, thought problems, attention problems, and other subscale scores. Sexual violence hurts the overall mental health of children who are abused, including their emotional, behavioral, and social factors. Our findings suggest that multidisciplinary assessment and treatment are required for children who have experienced sexual abuse.