PURPOSE: Studies have demonstrated beneficial health effects from yoga interventions in cancer patients, but predominantly in breast cancer. Research on its role in alleviating prostate cancer (PC) patients' side effects has been lacking. Our primary goal was to determine the feasibility of recruiting PC patients on a clinical trial of yoga while they underwent external beam radiation therapy (RT).METHODS: Twice-weekly yoga interventions were offered throughout the RT course (6-9 weeks). Baseline demographic information was collected. Feasibility was declared if 15 of the first 75 eligible PC patients approached (20%) were successfully accrued and completed the intervention. Additional end points included standardized assessments of fatigue, erectile dysfunction (ED), urinary incontinence (UI), and quality of life (QOL) at time points before, during, and after RT. RESULTS: Between May 2013 and June 2014, 68 eligible PC patients were identified. 23 patients (34%) declined, and 45 (56%) consented to the study. 18 (40%) were voluntarily withdrawn due to treatment conflicts. Of the remaining 27, 12 (30%) participated in ≥50% of classes, and 15 (59%) were evaluable. Severity of fatigue scores demonstrated significant variability, with fatigue increasing by week 4, but then improving over the course of treatment (P = .008). ED, UI, and general QOL scores demonstrated reassuringly stable, albeit not significant trends. CONCLUSIONS: A structured yoga intervention of twice-weekly classes is feasible for PC patients during a 6- to 9-week course of outpatient radiotherapy. Preliminary results are promising, showing stable measurements in fatigue, sexual health, UI, and general QOL.