Abstract Comprehensive Sexuality Education (CSE) is widely endorsed by several global organizations to promote adolescent development. However, in the Philippines, concerns about its implementation persist: parental resistance, cultural norms, and policy disputes. This qualitative study aimed to explore senior high school students' perceptions of. It focused on their thoughts on its introduction, the aspects shaping their beliefs, and the challenges they anticipate. This research employed a descriptive phenomenological approach in which 15 informants aged 16-19 are purposely selected. To gather the qualitative data, semi-structured interviews were conducted and analyzed through a thematic analysis. This study revealed strong support for CSE in minimizing teenage pregnancy rates and improving correct sexual health knowledge. The informants emphasized that cultural and familial norms, parental disapproval, and sensitivity to sexual topics are potential barriers to introducing CSE. The informants also highlighted some concerns, such as students not taking the matter seriously if CSE is introduced too early. Including age-appropriate rollouts is one of the themes discovered in this study. Lastly, community and parental engagements, together with teacher preparedness and training, can ensure an effective, respectful CSE learning environment. Keywords: Adolescent Sexual Health, Comprehensive Sexuality Education (CSE), Senior High School Students, Teenage Pregnancy