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Background: The hormonal fluctuations that occur during normal menstrual cycle has profound influence on autonomic functions. This influence on autonomic nervous system may affect cardiovagal control. The aim of the study is to find out the variation of Parasympathetic function tests during different phases of menstrual cycle in young healthy females.Methods: The present study was carried out on 50 healthy female subjects with normal menstrual cycles between the ages of 18 to 25 years. Various non-invasive parasympathetic function tests during different phases of menstrual cycle were performed that include Resting heart rate (RHR), Heart rate variation during deep breathing (E:I Ratio), Heart rate response to standing (30:15 Ratio), Heart rate response to Valsalva maneuver (Valsalva Ratio). The results were analysed using ANOVA and student’s paired-t tests.Results: During the menstrual cycle, we found varied heart rate response with higher values towards the luteal phase, when compared to the follicular phase and the menstrual phase. There was a statistically significant difference in the heart rate parameters like resting heart rate, 30:15 ratio, valsalva ratio and E:I ratio during the three phases of menstrual cycle.Conclusions: The study concludes that there was statistically significant heart rate variability during three phases of the menstrual cycle, as observed by the increased sympathetic discharge in the luteal phase compared to the increased parasympathetic discharge in the follicular phase. The results of our study have emphasized the complexity of the relationship between ovarian steroids and various hemodynamic regulatory systems.