Sympathetic & Parasympathetic test status may be changed during follicular and late luteal phases of menstrual cycle due to fluctuations of serum estrogen and progesterone levels. Objective is to find out. Sympathetic & Parasympathetic tests between male medical students & luteal phase of menstrual cycle in female medical students. This study evaluates autonomic function tests in different phases of menstrual cycle and concludes that sympathetic activity is highest during luteal phase and lowest in the follicular phase. It is concluded that there is higher sympathetic activity in males as compared to females