Background: Late effects of cancer and its treatment include pain, fatigue, stress, and depression, all mediated by autonomic dysfunction. Heart Rate Variability (HRV) coherence is an established measure of optimal autonomic function. HRV coherence is achieved when the heart beat-to-beat intervals increase and decrease with respiration in a smooth rhythm. High coherence is associated with improved mood, cognition, executive function, and optimal pulmonary gas exchange. Cancer survivors have lower HRV than controls. Low HRV has been associated with early mortality, inflammation, and other adverse intermediary outcomes. HRV biofeedback (HRV-B) training improves HRV coherence, restores autonomic health, and reduces the above symptoms. HRV-B is non-pharmacologic, inexpensive, and self-maintained. This report describes a feasibility study of HRV-B in symptomatic cancer survivors. Methods: In a randomized, waitlist-controlled clinical trial, 179 were screened, 35 enrolled and 31 completed the protocol. Participants in the intervention arm received weekly HRV-B training up to six weeks. Outcome measures assessed at baseline (pre) and after week six (post) included HRV coherence plus the Brief Pain Inventory (BPI), Multi-Dimensional Fatigue Inventory (MFI), Perceived Stress Scale (PSS) and Beck Depression Inventory II (BDI-II). Data analyzed using linear-mixed models for repeated measures (SAS Proc Mixed). Results:Conclusions: Delivering HRV Biofeedback training to cancer survivors is feasible in a clinical setting. This study provides preliminary evidence that HRV-B training for cancer survivors improves HRV and reduces pain, fatigue, stress, and depression. HRV-B training has potential for symptom control in cancer survivors. Controlled, multisite studies are indicated.