This qualitative study explores how comprehensive sexuality education located within a broader positive youth development approach informed transformations among young people from informal urban communities in India. A thematic analysis of data obtained from the young people, their parents, and frontline workers revealed that securing the cooperation of families was possible for the program because sexual and reproductive health education was not a stand-alone intervention, but a part of a larger approach seeking to build capacities of young people. The strategic introduction of sexual and reproductive health communication helped the participants to overcome inhibitions about the topic. Enhanced awareness of gender, pubertal changes, gender-based violence, and child sexual abuse was evidenced post participation. Improved agency was manifest through decision making, critical thinking, confidence, mobility, and articulation, especially among girls. Program interventions to enhance sexual and reproductive health awareness of parents and communities and to improve health services and facilities were bolstered through youth engagement. Such contribution by the young reinforced their knowledge and skills, strengthened agency, and cemented family and community support. A holistic program situated within the positive youth development approach thus seemed a pragmatic vehicle to promote comprehensive sexuality education for young people in vulnerable urban communities.