Impact for Veterans: Chronic low back pain (CLBP) is a highly prevalent condition for veterans, especially those who were actively deployed in military conflicts. In addition to chronic pain, CLBP leads to significant amounts of disability, reduced health-related quality of life (HRQOL), and increased health care utilization. Existing treatments for CLBP typically have small to moderate effects, and patients often seek additional treatment options. Yoga is an inexpensive treatment option with increasing evidence supporting its efficacy. However, it has not been studied among veterans with CLBP. Project Background: Chronic low back pain is highly prevalent, especially among veterans who were actively deployed. CLBP has been shown to result in more disability, higher health care utilization, reduced productivity, and lower HRQOL. Existing treatments for CLBP such as medication, physical therapy, exercise, and spinal manipulation have been shown to have small to moderate effects. Since patients live with chronic conditions for many years, and often for the rest of their lives, they appreciate being able to choose the treatments that best fit with their current values and preferences. In addition, some of these existing treatments are less expensive to provide than others, often because they are delivered in group format. Pilot data from a clinical yoga program show decreases in pain and depression, and increases in energy and HRQOL among veterans with CLBP. Primary Objectives: Our primary objective is to conduct a randomized trial, in which the health outcomes of veterans assigned to yoga is compared to the health outcomes of veterans assigned to delayed treatment with yoga. Our primary hypothesis is that veterans with CLBP assigned to the yoga will have improvements in functional ability that are significantly greater than the comparison group that does not receive yoga right away. Secondary outcomes include pain, psychological symptoms, energy, and HRQOL. Project Methods: We will recruit 144 VA patients with CLBP through VA primary care, pain service, physical therapy, and behavioral medicine clinics. Patients will be screened to ensure they can participate safely. Eligible patients will be randomized to yoga therapy or to the delayed treatment comparison group, which will be allowed to start yoga 12 weeks later. Yoga therapy consists of twice weekly yoga sessions led by a certified yoga practitioner for 12 weeks. Patients are encouraged to practice yoga postures at home unless their pain increases. The comparison group agrees to not participate in yoga or similar interventions for 12 weeks. Otherwise, both groups receive care as usual. Questionnaire data, medical record data, and some physiological data will be collected at baseline, 12 weeks, and at a 6-month follow-up. The main outcome data will be analyzed using ANCOVA and linear random effects models.