Problems with nightmares are reported by a sizable proportion of individuals with a history of trauma and by approximately 5% to 8% of the general population. Chronic nightmares may represent a primary sleep disorder rather than a symptom of a psychiatric disorder, and direct targeting of nightmares is a feasible clinical approach to the problem. Of the treatments proposed, imagery rehearsal therapy (IRT) has received the most empirical support. An up-to-date account of this cognitive-imagery approach shows how to treat nightmares during 4 roughly 2-hr sessions. The main points covered in each therapy session and their underlying rationale are presented. Dismantling protocols are suggested to discern active ingredients of IRT and to develop flexible applications based on patients' needs.