A tool for conducting in-depth assessments of trauma-induced psychological reactions, especially PTSD, in school-aged children and adolescents. Administration criteria for the tool are rather flexible—it can be administered in a self-report format, either individually or in a group setting, or orally by an interviewer. The tool, adapted from the Child Post-Traumatic Stress Disorder Reaction Index (CPTSD-RI) exists in three versions—Child (ages 6 to 12 years), Adolescent (13 years or older), and Parent’s Report. All three versions of the UCLA PTSD-RI are comprised of questions corresponding to the DSM-IV‘scriteria for PTSD. The Child version consists of 20 items, and the Adolescent and Adult versions contain 22 items. All versions of the questionnaire are divided into three parts: Parts I, II, and III. Part I addresses a child’s traumatic experience (Criterion A1 for PTSD from the DSM-IV). Part II, containing Yes/No response options, assesses cognitive and emotional reactions to the distressing event (Criterion A2 for PTSD from the DSM-IV). Part III delves into the frequency of PTSD symptoms in the past month, based on the classic PTSD triad of behavioral disturbances—avoidance, intrusion, and arousal (PTSD Criterion B, C, and D from the DSM-IV). Response options for items are—None of the Time (0), Some of theTime (1), Much of the Time (2), and Most of the Time (4). Two additional items address fear of recurrence and guilt related to trauma. Responses can be used to calculate a total score, and/or subscale values. The tool takes about 20-30 minutes to administer, and can be administered repeatedly.