Cognitive-behavioral treatments (CBTs) that target nightmares are efficacious for ameliorating self-reported sleep problems and psychological distress. However, it is important to determine whether these treatments influence objective markers of nightmare-related fear, because fear and concomitant physiological responses could promote nightmare chronicity and sleep disturbance. This randomized, controlled study (N=40) assessed physiological (skin conductance, heart rate, facial electromyogram) and subjective (displeasure, fear, anger, sadness, arousal) reactions to personally relevant nightmare imagery intended to evoke nightmare-related fear. Physiological assessments were conducted at pretreatment as well as 1-week, 3-months, and 6-months posttreatment. Results of mixed effects analysis of variance models suggested treatment reduced physiological and subjective reactions to nightmare imagery, gains that were generally maintained at the 6-month follow-up. Potential implications are discussed.