Natural menopause is characterized by gradual decrease in reproductive hormones i.e; Estrogen and Progesterone. However it is well known since long about the cardio protective effect of Estrogen because of which premenopausal women are more protected than age matched males. Cardiovascular system is mostly controlled by autonomic regulation through activity of sympathetic and parasympathetic pathways of Autonomic Nervous Systems (ANS). Analysis of HRV permits insight in this control mechanism. Materials and methods: A total of 60 healthy female volunteers participated in the study of which 30 were pre–menopausal women and 30 post menopausal women. ECG was recorded in Lead II for 5 min on Student Physio–pac. Cardiac Autonomic Nerve Function was determined using Heart Rate Variability (HRV) indices in the Frequency Domain. Data between study group was compared using students unpaired‘t’ test. Conclusion: There was enhanced Sympathetic dominance indicating reduction in Cardiac Autonomic modulation in post menopausal women compared to that of pre–menopausal women.