The inclusion of Persistent Complex Bereavement Disorder (PCBD) in the DSM-5 appendix signifies a call for research regarding the distinguishing features and clinical utility of proposed PCBD criteria. Rigorously constructed tools for assessing PCBD are lacking, especially for youth. This study evaluated the validity and clinical utility of the PCBD Checklist, a 39-item measure designed to assess PCBD criteria in youth aged 8 to18 years. Test construction procedures involved: (a) reviewing the literature regarding developmental manifestations of proposed criteria, (b) creating a developmentally informed item pool, (c) surveying an expert panel to evaluate the clarity and developmental appropriateness of candidate items, (d) conducting focus groups to evaluate the comprehensibility and acceptability of items, and (e) evaluating psychometric properties in 367 bereaved youth (M_age = 13.49, 55.0% female). The panel, clinicians, and youth provided favorable content validity and comprehensibility ratings for candidate items. As hypothesized, youth who met full PCBD criteria, Criterion B (e.g., preoccupation with the deceased and/or circumstances of the death), or Criterion C (e.g., reactive distress and/or social/identity disruption) reported higher posttraumatic stress and depressive symptoms than youth who did not meet these criteria, η_p² = .07-.16. Youth who met Criterion C reported greater functional impairment than youth who did not, η_p² = .08-.12. Youth who qualified for the "traumatic bereavement specifier" reported more frequent posttraumatic stress symptoms than youth who did not, η_p² = .04. Findings support the convergent, discriminant, and discriminant-groups validity, developmental appropriateness, and clinical utility of the PCBD Checklist.