Background of the study: Developing country like India, the status of nutrition in women is least attended. Malnutrition, vitamin and mineral deficiencies results in many disorders including Pre menstrual symptoms. Equal to men, the women in India, considered as backbone in the family and society. From the ancient period, the health of the women especially menstrual problems has been neglected. Epidemiologic surveys have estimated that as many as 80% of women of reproductive age experience some symptoms attributed to the premenstrual phase of the menstrual cycle. Objectives of the study: To evaluate the effectiveness of structured teaching program on knowledge regarding prevalence and management of Pre-menstrual syndrome among adolescent girls. Materials and Methods: The research approach used in this study was Evaluative in nature and design adopted was pre-experimental one group pre test -post test design. Total of 60 adolescent girls were selected by using Non Probability Purposive sampling technique. A structured online questionnaire (Google Forms) method was used to assess the knowledge of students regarding prevalence and management of Premenstrual syndrome on 1 s t and 14 t h Day of Data collection. On 7 t h day investigators administered the Structured teaching Programme through Online platform (Google meet). Data was analyzed using descriptive and inferential statistics. Results: Most (48.3%) of the subjects in the pre-test had moderate knowledge regarding prevalence and management of pre-menstrual syndrome, whereas in the post-test all the subjects (100%) had scored between 23 and 35 indicating adequate knowledge. Pre-test and post-test knowledge score of subject ranged between 09-32 and 23-35 respectively. The mean pre-test and post-test knowledge score of subjects was 19.1 and 28.46 respectively. The mean post-test knowledge score was significantly higher than mean pretest knowledge score (t =9.36) at 0.05 level of significance (t (59) =2.0,). There was significant association between participants pre test knowledge scores with their age and dietary habits. Conclusion:The study proved that students had inadequate knowledge on pre-menstrual syndrome during pretest. After administration of the structured teaching programme their knowledge improved to a remarkable extent. The findings of the study showed that the structured teaching programme was effective in increasing the knowledge of students on prevalence and management of pre-menstrual syndrome.