Objective The percentage of repeat offenders is increasing among juvenile offenders in Korea. The assessment and treatment of the mental health of young offenders may play an important role in reducing the recidivism rate of adolescents. This study examined the prevalence of psychiatric disorders among adolescents on probation or parole and the risk of recidivism associated with specific psychiatric disorders. Methods We studied 120 adolescents on probation. The Mini-International Neuropsychiatric Interview and Conners’ Rating Scale-Revised were used to diagnose psychiatric disorders. Results Almost half of the juvenile offenders had psychiatric disorders, including alcohol use disorder (19.17%), bipolar disorder(18.33%), antisocial personality disorder (11.67%), and attention-deficit/hyperactivity disorder (10.83%). Alcohol use disorder was significantly associated with repeated offenses, but psychiatric disorders, excluding alcohol use disorder, were not significantly associated with repeated offenses. Conclusion These results suggested that the development of education and treatment programs for psychiatric disorders, including alcohol use disorder, among juvenile offenders on probation or parole may help to prevent repeated criminal behaviour.