Background: Many debilitating symptoms arise from cancer and its treatment that are often unrelieved by established methods. Pranayama, a series of yogic breathing techniques, may improve cancer-related symptoms and quality of life, but it has not been studied for this purpose.Objectives: A pilot study was performed to evaluate feasibility and to test the effects of pranayama on cancerassociated symptoms and quality of life. Design: This was a randomized controlled clinical trial comparing pranayama to usual care. Setting: The study was conducted at a university medical center. Subjects: Patients receiving cancer chemotherapy were randomized to receive pranayama immediately or after a waiting period (control group). Interventions: The pranayama intervention consisted of four breathing techniques taught in weekly classes and practiced at home. The treatment group received pranayama during two consecutive cycles of chemotherapy. The control group received usual care during their first cycle, and received pranayama during their second cycle of chemotherapy. Outcome measures: Feasibility, cancer-associated symptoms (fatigue, sleep disturbance, anxiety, depression, stress), and quality of life were the outcomes. Results: Class attendance was nearly 100% in both groups. Sixteen (16) participants were included in the final intent-to-treat analyses. The repeated-measures analyses demonstrated that any increase in pranayama dose, with dose measured in the number of hours practiced in class or at home, resulted in improved symptom and qualityof-life scores. Several of these associations—sleep disturbance ( p = 0.04), anxiety ( p = 0.04), and mental quality of life ( p = 0.05)—reached or approached statistical significance. Conclusions: Yoga breathing was a feasible intervention among patients with cancer receiving chemotherapy. Pranayama may improve sleep disturbance, anxiety, and mental quality of life. A dose–response relationship was found between pranayama use and improvements in chemotherapy-associated symptoms and quality of life. These findings need to be confirmed in a larger study.