Methodology: The study aimed to assess initial knowledge levels on menstrual hygiene among adolescent girls via a pre-test, followed by evaluating the effectiveness of a structured teaching programme. It sought to establish correlations between pre-test and post-test scores, and explore associations with demographic variables. Conducted at Stani Memorial Public School in Phagi, Jaipur, the research included 60 girls aged 12 to 18 using simple random sampling. The instrument featured demographic data and a structured questionnaire on Anatomy & Physiology, Menstruation Facts, and Menstrual Hygiene, demonstrating high reliability (0.9532).

Results: The study conducted a comprehensive area-wise comparison of pre and post-test scores among adolescent girls, highlighting significant improvements in knowledge following a structured teaching programme (STP). The highest pre-test mean score of 2.88±1.843 (32.48%) was in "Menstrual Hygiene," while the lowest was 3.28±1.085 (28.67%) in "Anatomy and Physiology of the Reproductive System." Post-test scores showed substantial enhancement, with "Menstrual Hygiene" leading at 7.63±0.855 (63.23%) and "Anatomy and Physiology" at 5.78±0.961 (56.83%). The mean percentage differences were notable, particularly in "Menstrual Hygiene" (37.08%) compared to "Facts related to menstruation" (33.19%). Overall, pre-test mean percentage was 30.87%, increasing significantly to 66.54% post-test, reflecting a 35.67% improvement attributable to the STP. The paired t-test affirmed these findings, with specific values confirming significant differences in knowledge scores (Anatomy & Physiology: 18.563, Facts related to menstruation: 12.436, Menstrual hygiene: 17.821, overall: 32.189; all p< 0.05). While demographic variables showed no significant associations with post-test scores, the source of information did (p< 0.05), emphasizing the STP's efficacy in improving adolescent girls' knowledge on menstrual hygiene.

Conclusion: The findings underscore the effectiveness of targeted educational interventions in enhancing understanding and practices related to menstrual health.