Objective : To study the effect of premenstrual stress on cardiovascular system of young girls. Methods : Hffect of premenstrual stress on cardiovascular system i.e. pulse rate, blood pressure and weight were studied on 70 healthy young girls between the age of 18 to 25 years during premenstrual and postmenstrual phases. Results : There were significant increase in pulse rate, blood pressure (both systolic and diastolic), weight during premenstrual period as compared to postmenstrual period. Conclusions : These cardiovascular changes are due to fluid and salt retention which arc due to ovarian steroids and exaggerated response to hormonal changes.