Purpose: Several trials on noncancer population indicate that yoga is associated with meaningful clinical effects. This study evaluated the physical and psychosocial outcomes of yoga in oncologic patients treated with radiotherapy.Methods: We focused on a research through Cochrane Register of Controlled Trials (CENTRAL), BioMed Central, and MEDLINE studies up to May 2017. Results: Yoga was found to have a substantial benefit in cancer patients' distress, anxiety, and depression. It also demonstrated a moderate impact on fatigue and emotional function and a small and insignificant effect on functional well-being and sleep disturbances. As far as the effects on psychological outcomes are concerned, there was insufficient evidence. Conclusions: This systematic review of randomized controlled trials showed that yoga has strong beneficial effects on oncologic patients' quality of life. Results of the current review must be interpreted with caution due to the relative small sample sizes of most of the included studies, while a prospective randomized study stands in need for the confirmation of our results.