This study details results of an open trial of a group psychological treatment for Veterans with posttraumatic stress disorder (PTSD) and chronic posttraumatic nightmares called "Imagery Rescripting and Exposure Therapy" (IRET). IRET is a variant of a successful imagery rescripting treatment for civilian trauma-related nightmares that was modified to address the needs of the Veteran population. Thirty-seven male U.S. Veterans with PTSD and nightmares attended 6 multicomponent group sessions. Findings indicated that the intervention significantly reduced frequency of nightmares and PTSD severity, as well as increased hours of sleep. Unlike the few open trials examining treatment of nightmares in Veterans, effect sizes in this study were similar to those that have been found in the civilian randomized controlled trial. These preliminary findings suggest that a nightmares treatment can be adapted to successfully reduce distress associated with combat Veterans' chronic nightmares. Clinical and research implications are discussed.