OBJECTIVES:The aim of this study is to evaluate the efficacy and tolerability of Sudarshan Kriya Yoga (SKY) course in generalized anxiety disorder (GAD) outpatients, who after eight weeks of an appropriate dose of traditional therapy had not yet achieved remission. SUBJECTS: The adult participants (18-65 years) were outpatients with a primary diagnosis of GAD with or without comorbidities on the Mini-International Neuropsychiatric Interview (MINI). Participants had a minimum of eight weeks standard treatment with an appropriate dose of a standard prescription anxiolytic, a clinician global impression-severity (CGI-S) score of 5-7, a Hamilton anxiety scale (HAM-A) total score ≥20 including a score of >2 on the anxious mood and tension items. MATERIALS AND METHODS: Forty-one patients were enrolled in an open-label trial of the SKY course as an adjunct to standard treatment of GAD at the START Clinic for Mood and Anxiety Disorders, a tertiary care mood and anxiety disorder clinic in Toronto. The SKY course was administered over five days (22 h total). Subjects were encouraged to practice the yoga breathing techniques at home for 20 min per day after the course and were offered group practice sessions for 2 h once a week led by certified yoga instructors. The primary outcome measure was the mean change from pre-treatment on the HAM-A scale. Psychological measures were obtained at baseline and four weeks after completing the intervention. RESULTS: Thirty-one patients completed the program (mean age 42.6 ± 13.3 years). Among completers, significant reductions occurred in the pre- and post-intervention mean HAM-A total score (t=4.59; P<0.01) and psychic subscale (t=5.00; P≤0.01). The response rate was 73% and the remission rate 41% as measured on the HAM-A. CONCLUSION: The results of this small pilot trial suggest that the SKY course represents a potentially valuable adjunct to standard pharmacotherapy in patients with GAD or treatment-resistant GAD, and warrants further investigation. In particular, changes in worry and body symptoms showed significant improvements that may further our understanding of the mechanism of change in the tolerance of anxiety and worry.