This study assesses the optimal cut-off point for the Impact of Event Scale and compares its screening properties with those of the Self-rating Inventory for Posttraumatic Stress Disorder among war-related trauma victims. 74 patients with war-related trauma were administered the Impact of Event Scale and the Self-rating Inventory for Posttraumatic Stress Disorder, followed 1 wk. later by the Clinician-administered PTSD Scale. Receiver operating characteristic analysis indicated for the Impact of Event Scale a sensitivity of .77 and a specificity of .51 at a cut-off value of 36. For the Self-rating Inventory for Posttraumatic Stress Disorder a sensitivity of .86 and a specificity of .69 were found at a cut-off value of 52. The authors conclude that careful use of the Impact of Event Scale as a screening measure for Posttraumatic Stress Disorder is warranted.