OBJECTIVES: To evaluate the effects of pranayama and deep breathing exercises on fatigue and sleep quality in women undergoing radiation therapy for breast cancer. SAMPLE & SETTING: This randomized controlled study was conducted on the outpatient radiation oncology unit of a hospital with 20 patients each in pranayama, deep breathing, and standard care groups (N = 60). METHODS & VARIABLES: The Piper Fatigue Scale and the Pittsburgh Sleep Quality Index were used to evaluate the participants’ fatigue and sleep quality. RESULTS: The control group showed a significant increase in fatigue levels at the end of radiation therapy compared to the beginning. Sleep quality was improved only in the pranayama group. IMPLICATIONS FOR NURSING: Pranayama can be learned easily, can be performed anywhere, and does not require any equipment, making it a convenient exercise for patients. Oncology nurses can take the lead in suggesting pranayama for symptom management.