Background: Parents are blessed if they have girl child now a days. But, being the girls, they need to undergo physiological changes of menustration with the Un comfortable symptom of Premenstrual syndrome much during the Adolescent period till the menopause period during their life time. Premenstrual syndrome (PMS) is a frequent fitness trouble among adolescents. Objective: To assess the prevalence of PMS in Chennai high school students. Materialsandmethods: This used to be a potential study conducted amongst adolescent students in St, Lourdes Girls High school at chennai from July to August, 2018. Participants were asked to prospectively entry an anonymous questionnaire, which included facts about demographic data, menstrual patterns, and signs to be recorded on a each day calendar of premenstrual experiences according to the diagnostic standards proposed by the American College of Obstetricians and Gynecologists. All of the information have been prospectively recorded for 90 consecutive days. Results: of the 300 participants, 289 (72.4%) accomplished the self-report questionnaire. 203 contributors (29.8%; 95% CI, 24.5%–35.4%) pronounced having PMS. The most frequent somatic and affective signs and symptoms among participants with PMS were breast tenderness (74.4%) and angry outbursts (97.7%). There were tremendous differences between the PMS and non-PMS groups, and PMS was associated with a range of problems associated to educational activities, including lack of awareness and motivation, bad work performance, negative collaborative work performance, and low scores. However, there were no large variations regarding interpersonal relationships between the PMS and non-PMS groups. Conclusions: PMS is a frequent menstrual disorder amongst St. Lourdes school students. The most habitual symptoms suggested in this learn about have been angry outburst and breast tenderness.