Between 5 and 15 percent of Veterans return from deployment in Iraq and Afghanistan with PTSD and the symptoms adversely affect many aspects of their lives, including intimate relationships. Although research findings consistently suggest that the degree of intimate relationship dysfunction correlates with the severity of Veteran's PTSD symptoms, few couples interventions have been developed and systematically evaluated. Cognitive Behavioral Conjoint Therapy for PTSD (CBCT for PTSD) is an intervention developed to treat both PTSD and relationship dysfunction that has shown promising preliminary results. However, the literature suggests that OEF-OIF Veterans prefer shorter time-limited treatments and CBCT for PTSD requires as many as 15 sessions. CBCT for PTSD lacks specific interventions that train meta-awareness, such as those taught in mindfulness-based stress reduction (MBSR). Mindfulness practices have an emerging evidence base for improving both PTSD and relationship functioning in several important ways. First, practicing mindfulness promotes the relaxation response which counters hyperarousal and results in a calmer approach to difficulties and challenges. Second, avoidance and numbing are countered by mindfully allowing one's experience to be as it is while suspending judgment, which is associated with increased compassion and empathy. Lastly, mindfulness supports a way of being with all life experiences rather than providing techniques just for coping with specific difficulties, which enables individuals to access inner strengths that are already available to them. Just as many physical conditions require more than one rehabilitation approach, there may be a synergy between CBCT for PTSD and mindfulness interventions. Mindfulness skills may assist individuals in tolerating painful emotional reactions to their experiences which may in turn enhance their awareness of associated feelings and thoughts. With enhanced meta-awareness the beliefs that may maintain PTSD symptoms and relationship dysfunction become more amenable to cognitive restructuring. Therefore, the goal of this study is to examine the effects of a Mindfulness-Based adaptation of CBCT for PTSD. The study involves two phases over the course of four years. In Phase 1, mindfulness interventions will be integrated within the Cognitive Behavioral Conjoint Therapy for PTSD treatment manual and the content of the first 7 sessions of CBCT will be adapted to be delivered during a weekend retreat. The integrated intervention, MB-CBCT for PTSD, will be delivered to 10 OIF-OEF Veterans and each of their intimate partners in order to develop and test procedures to train and monitor therapists. During Phase 2, 40 OEF-OIF Veterans and each of their intimate partners will be consented and a randomized controlled trial with be conducted comparing the MB-CBCT for PTSD with a control condition that teaches communication skills drawn from the first 7 sessions of the CBCT manual. We hypothesize that MB-CBCT for PTSD will lead to greater improvement in: 1) Veterans' PTSD symptoms as measured by the Clinician Administered PTSD Scale (primary outcome) and PTSD Checklist (secondary outcome); 2) Veterans' and partners' relationship functioning (secondary outcome); and 3) anxiety and depression symptoms (secondary outcomes). PTSD constitutes a substantial proportion of the burden of illness among Veterans. The longer term goals of this project are to conduct a fully-powered randomized controlled clinical trial of MB-CBCT to determine its effectiveness and to finalize the treatment manual.