The Acute Stress Disorder Scale (ASDS) is a self-report inventory that (a) indexes acute stress disorder (ASD) and (b) predicts posttraumatic stress disorder (PTSD). The ASDS is a 19-item inventory that is based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV, American Psychiatric Association, 1994) criteria. The ASDS possessed good sensitivity (95%) and specificity (83%) for identifying ASD against the ASD Interview on 99 civilian trauma survivors. Test-retest reliability of the ASDS scores between 2 and 7 days was strong (r = .94). The ASDS predicted 91% of bushfire survivors who developed PTSD and 93% of those who did not; one third of those identified by the ASDS as being at risk did not develop PTSD, however. The ASDS shows promise as a screening instrument to identify acutely traumatized individuals who warrant more thorough assessment for risk of PTSD.