The purpose of this study was to investigate the characteristics of problem behaviors, cultural identity and acculturation of North Korean (NK) refugee youth and to suggest an appropriate approach for helping them to adjust to our society based on these findings. Methods: The subjects were 117 NK adolescent refugees in Hanawon. Data were collected by a demographic questionnaire, Youth Self Report (YSR), the South-North Korean cultural identity. Results: Problem behaviors of NK refugee youth were the highest in anxiety/depression and withdrawal behavior and were followed by internalized behavior, aggressiveness, overall problem behavior, externalized behavior, delinquency and positive behavior in that order. Acculturation was the highest in ``separation`` followed by ``integration``, ``assimilation`` and ``marginalization`` in that order. No significant relationship was found between acculturation types and problem behaviors except positive behavior. Conclusion: This study provides some important information that we have to develop specific strategies and interventions primarily focused on withdrawal, anxiety/depression, and internalization for the adjustment and mental health of NK refugee youth. It is necessary to explore further research related to cultural identity, acculturation processes, and the correlation between acculturation types and problem behaviors.