Sudarshan Kriya Yoga (SKY) is a standardized series of breathing techniques that has beneficial effects on the heart and the immune system (Brown et. al., 2005) in healthy and specific health-compromised populations. We wish to assess if SKY can be feasibly applied in patients with PTSD that are seen in the routine psychiatry clinic. Additionally, we will explore if SKY has a positive response on heart rate control and the immune stress response in these patients.