Prolonged exposure (PE) therapy has been found efficient in reducing posttraumatic stress disorder (PTSD) symptoms mostly among rape victims, but has not been explored in combat-related PTSD. Five patients with severe chronic PTSD, unresponsive to previous treatment (medication and supportive therapy) are described. Patients were evaluated with the PTSD Symptom Scale-Interview, and Beck Depression Inventory, before and after 10-15 sessions of PE therapy. All five patients showed marked improvement with PE, with a mean decrease of 48% in PTSD Symptom Scale-Interview score and 69% in Beck Depression Inventory score. Moreover, four patients maintained treatment gains or kept improving 6-18 months after the treatment. The results suggest that PE was effective in reducing combat-related chronic PTSD symptoms.