INTRODUCTION: Interest in the application of yoga for health benefits in western medicine is growing rapidly, with a significant rise in publications. The purpose of this systematic review is to determine whether the inclusion of yoga therapy to the treatment of breast cancer can improve the patient's physical and psychosocial quality of life (QoL). METHODS: A search of peer reviewed journal articles published between January 2009 and July 2014 was conducted. Studies were included if they had more than 15 study participants, included interventions such as mindfulness-based stress reduction (MBSR) or yoga therapy with or without comparison groups and had stated physical or psychological outcomes. RESULTS: Screening identified 38 appropriate articles. The most reported psychosocial benefits of yoga therapy were anxiety, emotional and social functioning, stress, depression and global QoL. The most reported physical benefits of yoga therapy were improved salivary cortisol readings, sleep quality and lymphocyte apoptosis. Benefits in these areas were linked strongly with the yoga interventions, in addition to significant improvement in overall QoL. CONCLUSION: The evidence supports the use of yoga therapy to improve the physical and psychosocial QoL for breast cancer patients with a range of benefits relevant to radiation therapy. Future studies are recommended to confirm these benefits. Evidence-based recommendations for implementation of a yoga therapy programme have been derived and included within this review. Long-term follow-up is necessary with these programmes to assess the efficacy of the yoga intervention in terms of sustainability and patient outcomes.