Patients with Wilson's disease (WD) are at increased risk of poor quality of life (QoL) and social-emotional outcomes. The above data has been well established in the adult population. What are the predictors of QoL in children and adolescents with WD are unknown. Our study examined whether subjective feelings about QoL are related to the psychosocial functioning in paediatric patients. A cross-sectional study among 50 children with WD, aged 7-18 years. Participants completed the KINDL QoL questionnaire and the Child Behavior Checklist assessing internalizing and externalizing behaviors. Internalizing and externalizing behaviors and their interaction are significant in predicting the QoL of children with WD. Internalizing behaviors are significant predictor of the QoL β = -0.328 (p < 0.05). The effect of internalizing behavior on the QoL varies with the level of externalizing behavior β = -0.344* (p < 0.05). Simple effects analysis indicates that the highest QoL for children with WD is in the group characterized by both low levels of internalizing and medium levels of externalizing behaviors, t = -3.052 (df = 46) and p < 0.01, or high levels of externalizing behaviors, t = -2.725 (df = 46) p < 0.01. The interaction between internalizing behaviors explained an additional 7.5% of the variance in scores on the QoL scale. Overall, the final regression model explained 14.9% of the scores on the QoL scale. Monitoring internalizing and externalizing behaviors will allow a better understanding of the course of treatment. In chronic disease, the QoL is an aspect that determines the doctor-patient relationship and often determines the course of the therapeutic process.