Objectives : The aim of this study was to examine the relationship between internet game addiction and psychiatric symptoms. Methods : A total of 447 adolescents who were recruited from a child and adolescent psychiatric clinic of university hospital completed a self-report questionnaire consisting of Korean Internet Addiction Self-scale (K-scale), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Korean-Attention-Deficit Hyperactivity Disorder Rating Scale (K-ARS), and Adolescent Happiness Index (AHI). They were classified into three internet user groups, non-addicted group (below or equal to 94), potential risk group (95 to 107) and high risk group (above or equal to 108) according to K-scale total score. Results : Significant mean differences in BDI, BAI, K-ARS, and AHI scores were observed among the three groups. The BDI, BAI and K-ARS scores showed positive correlation with K-score. The AHI score showed negative correlation with K-score. Conclusion : Findings of this study suggest that depression, anxiety, inattention, hyperactivity/impulsivity, and happiness are associated with internet game addiction.