Children with juvenile idiopathic arthritis (JIA) are prone to the problems that can delay their psychosocial development; however, the existing literature has not reached a consensus on the psychological problems related to JIA. A total of 51 children and adolescents with JIA and 75 healthy controls aged 6 to 18 years were examined using the Child Behavioral Checklist (CBCL). Our results represented that 70 percent of JIA group reached "borderline clinical" range or "clinical" range in internalizing problems, while this percentage in the control group was 18 percent. In addition, our results indicated that JIA group has gotten significantly higher scores (more than twofold) in externalizing behaviors compared to control group. Furthermore, children with JIA showed higher rate of anxiety/depression, withdrawal/depression, somatic complaints, rule breaking behaviors, and aggressive behaviors as well as thought and social problems compared to control group (p < 0.001). As a conclusion, children and adolescents with JIA compared to healthy controls may show higher rate of both internalizing and externalizing problems. Furthermore, our novel findings on externalizing, social, and thought problems in JIA warrant further investigation on affected children who may be at greater risk of future psychopathologies.