Purpose: The purpose of this study was to describe health problems and psychosocial adaptation in children with cancer and to determine the relationship between these two variables. Method: The data were collected from parents of 61 children with cancer, aged 4-11 years at one university hospital in Seoul. The instruments for this study were the Korea Child Behavior Check List (KCBCL) and a physical symptom checklist developed by the researchers. Result: The major health problems were coughing, sleeping disturbances, fatigue and weakness. The total behavior problem score for children in the cancer group was higher than the score for those in the norm group. The scores on the scales for withdrawal, somatic complaints, social immaturity, and internalizing problems were higher in the children with cancer compared to normative findings. Scores on social and school competence in the cancer group were lower than the norms for healthy children. The relationship between health problems and psychosocial adaptation was significant in the subscales of withdrawal, anxiety/depression, internalizing problems and social involvement in the off therapy group. Conclusions: This study shows the various areas that need further study in caring for children with cancer.