Background: Menstrual hygiene is a crucial aspect of adolescent health, impacting the well-being and dignity of school girls. In central Haryana, where a significant population of adolescent girls resides, there is a need to understand the knowledge, attitudes, and practices of school girls regarding menstrual hygiene. This study, conducted among 200 adolescent school girls, aims to fill this gap by assessing these factors and providing insights for targeted interventions. Methods: A cross-sectional study was conducted among 200 adolescent school girls aged 10-18 in central Haryana from 2020 to 2021. A self-designed questionnaire was administered to collect data on socio-demographic characteristics, knowledge, attitudes, and practices related to menstrual hygiene. SPSS version 24 was used for data analysis, employing the Chi-square test to identify associations between variables. Results: The study revealed that, among the 200 adolescent school girls in central Haryana, 68.3% considered menstruation a normal process, while 46.7% had good knowledge scores. However, concerning percentages, 30.8% were uncertain about menstrual blood hygiene, and 53.3% were categorized as having poor knowledge. Addressing these knowledge gaps is crucial for promoting menstrual hygiene and the well-being of school girls in the region. Conclusions: The findings emphasize the importance of addressing the knowledge gaps and misconceptions surrounding menstrual hygiene among school girls in central Haryana, where this study involved 200 adolescent participants. Targeted educational programs involving mothers and teachers as key influencers are essential to improving girls understanding and promoting better menstrual hygiene practices. This research serves as a foundation for empowering school girls with knowledge and promoting their overall well-being.