Abstract  Posttraumatic nightmares are a hallmark of PTSD and distinct from general nightmares as they are often repetitive and faithful representations of the traumatic event. This paper presents data from a pilot study that examined the use of Imagery Rehearsal in treating combat-related nightmares of 12 Vietnam veterans with PTSD. Three treatment groups, comprising 4 veterans in each, completed standardised treatment across 6 sessions. Treatment effects were investigated using nightmare diaries and established instruments, including the IES-R, BDI, BAI, and SCL-90-R. The data demonstrate significant reductions in nightmares targeted, and improvements in PTSD and comorbid symptomatology. The paper recommends that, on the basis of the promising preliminary data, a randomised control trial be established to assess imagery ability and attidude toward nightmares.