The psychometric properties of the PTSD Checklist (PCL), a new, brief, self-report instrument, were determined on a population of 40 motor vehicle accident victims and sexual assault victims using diagnoses and scores from the CAPS (Clinician Administered PTSD Scale) as the criteria. For the PCL as a whole, the correlation with the CAPS was 0.929 and diagnostic efficiency was 0.900 versus CAPS. Examination of the individual items showed wide ranging values of individual item correlations ranging from 0.386 to 0.788, and with diagnostic efficiencies of 0.700 or better for symptoms. We support the value of the PCL as a brief screening instrument for PTSD.