This study evaluates knowledge of HIV post-exposure prophylaxis (PEP) among sexually active adolescent girls and young women (AGWY) in Eswatini, a population disproportionately at risk of and affected by HIV. It finds that PEP awareness was low, highlighting gaps in access to HIV prevention knowledge among this population despite their elevated risk. The findings underscore the importance of integrating PEP education into HIV prevention programmes, sexual and reproductive health services, and school-based curricula, while also demonstrating the need for gender-responsive strategies that make HIV prevention information more accessible and relevant to adolescent girls and young women.