This review describes the results of all published research reports and dissertations through September 2011 that have evaluated or used the Massachusetts Youth Screening Instrument-Version 2 (MAYSI-2). The instrument was released in 2000 and is now widely used in the U.S. for brief mental health screening at entry to juvenile justice programs. The research found adequate psychometric properties, internal consistency and relationships to other validated tools measuring similar constructs. The review suggests several cautions for the clinical application of this instrument. First, it should be used to identify youth for further assessment and mental health consultation and not for providing diagnoses or long-term treatment plans. Second, evidence only supports its use in its intended contexts, in juvenile justice programs with youth soon after admission. The paper concludes by offering suggestions for future research.