Background- Patients on chemotherapy frequently presented with signs and symptoms of autonomic dysfunction. Cardiac autonomic dysfunction (CAD) is a significant cause of morbidity, mortality and affects the quality of life with progressive advancing disease and is associated with short survival of cancer patients. Therefore a thorough assessment of cardiovascular autonomic functions is crucial to monitor the disease prognosis and chemotherapy side effects on these patients. The present study was done to evaluate baseline Heart Rate Variability (HRV) and Ewings battery of Cardiac autonomic reactivity tests in cancer patients on chemotherapy to evaluate CAD