We assessed the heart rate, skin conductance, and left lateral frontalis electromyographic responses of World War II (WWII) and Korean War male veterans to recollection of their combat experiences by using a script-driven imagery technique previously validated in Vietnam veterans (Pitman et al., 1990; Pitman, Orr, Forgue, de Jong, & Claiborn, 1987). Medication-free subjects were classified on the basis of criteria from the revised third edition of the Diagnostic and Statistical Manual of Mental Disorders into posttraumatic stress disorder (PTSD; n = 8) and non-PTSD (n = 12) groups, which did not differ in over-all combat exposure or severity of personal combat events. PTSD subjects' physiological responses during personal combat imagery were markedly larger than those of non-PTSD subjects, even though the self-reponed emotional responses of the two groups were comparable. A physiological discriminant function derived from Vietnam veterans (Orr et al, 1990) correctly classified 7 of the 8 PTSD subjects (sensitivity was 88%) and 12 of the 12 non-PTSD subjects (specificity was 100%; p < .001).