In the U.S., the Massachusetts Youth Screening Instrument-Second Version (MAYSI-2) has been shown to be a reliable and valid tool to identify youth with mental health needs upon entry in detention facilities. The present study examined the factor structure, internal consistency, and convergent validity of the Dutch MAYSI-2 administered as part of routine clinical assessments in up to 955 detained male adolescents. Standardized mental health screening questionnaires (Youth Self-Report and Strengths and Difficulties Questionnaire) were used to test the convergent validity of the Dutch MAYSI-2. Confirmatory factor analyses showed that the factor structure of the original MAYSI-2 could be replicated with the Dutch MAYSI-2. Internal consistency indices showed that the Dutch MAYSI-2 provides a reliable screening of mental health needs. In addition, the Dutch MAYSI-2 scales were related with conceptually parallel measures of the same targeted mental health needs in the total group. With a few exceptions, the internal consistency and convergent validity was supported across ethnic groups as well. Overall, these results suggest the psychometric properties of the Dutch MAYSI-2 to be promising. Implications and limitations of the current study’s findings and directions for future research are discussed.