Objective: The aim of this study is to examine the concurrent validity of the Trauma Symptom Checklist for Children (TSCC) using associated behavioral health diagnoses. Methods: The sample included 2,544 youth participating in a juvenile justice diversion program for youth with behavioral health issues. Youth received a full diagnostic assessment and completed the TSCC. Analyses of variance examined the relationship between TSCC subscale scores and behavioral health diagnoses. Results: The TSCC subscales were often able to differentiate between youth with and without "Diagnostic and Statistical Manual of Mental Disorders" diagnoses of different classes. For example, youth diagnosed with generalized anxiety disorder (GAD) reported significantly higher means on the TSCC Anxiety Scale than did youth without GAD. Conclusions: The TSCC is a popular trauma symptomatology screening tool, and the current study provides support for its concurrent validity with behavioral health diagnoses. The TSCC provides helpful information that can serve to reinforce clinical decisions around diagnoses and treatment planning.