<p>Globally, an inadequate <i>“knowledge-practice gap”</i> of health and hygiene information remains a major concern, affecting the health of children and women, specifically from vulnerable groups, which further contributes to a significant challenge of preventable diseases. In light of that, this study intends to understand girls’ current knowledge of health and hygiene, and to identify socio-cultural and institutional influences affecting their health knowledge and hygiene practices. Carried out in four government schools in Panchkula district of Haryana (a peri-urban district), India, the study primarily draws upon qualitative data supported by survey-based information collected from 319 adolescent girls. This was further supplemented by interviews with educators, administrators and parents of the children. The collected data were analysed using Braun and Clarke’s method of thematic analysis (<CitationRef CitationID="CR4">2006</CitationRef>). The results highlight that physical health is usually well understood, while mental and social health awareness pose a greater challenge. Menstrual hygiene awareness has increased; however, it is still hindered by the cultural taboo, especially in rural areas. While health support exists at the institutional level, infrastructural challenges remain. The study will help policy planners and health practitioners gain localised insights into socio-cultural and institutional factors shaping adolescent girls’ health and hygiene in order to provide more effective and context-sensitive interventions.</p>