We examined the interrater reliability of the "Child and Adolescent Needs and Strengths-Mental Health" (CANS-MH) scale among researchers and between researchers and clinicians. All children presenting to a treatment facility for either protective or mental health needs were eligible to be included in the study. As part of standard assessment procedure, all children entering the facility were described by caseworkers using the CANS-MH. A random sample of 60 cases was selected and researchers made retrospective assessments using the CANS-MH based on chart review. Results of the interrater reliability support previous findings that the CANS-MH is a reliable measure of clinical and psychosocial needs and strengths. Results also suggest that ratings on the CANS-MH based on medical record abstraction by researchers relate to ratings performed by clinical staff, demonstrating the clinical and research utility of the CANS-MH. The CANS-MH can be used reliably to assess the type and severity of problem presentation, risk behaviors, functioning, care intensity and organization, caregiver capacity and strengths among children with protective and mental health needs. In addition, items of the CANS-MH appear to be reliable supporting the use of these items individually. Findings are relevant to the ongoing delivery of clinical services, monitoring of quality assurance, and outcomes.