Sexual health is a signficant dimension of health among children and youth in Tanzania. Local discourses highlight concerns regarding HIV/AIDS and sexual violence. The aim of this study was to examine the experiences and participation of children and youth in sexual health-related discussions, decisions, and actions in Njombe; a Tanzanian rural community. A focused ethnography, with a participatory approach, was conducted over a 3.5 month period, using participant observation, group interviews, and analysis of key texts, as well as key informant advisors. Twenty-eight participants, 8–16 years of age, were recruited from a community Youth Peer Health Educator program and an HIV youth group. Four principal themes were identified: (a) knowledge and understanding of sexual health, (b) children/youth value sexual health education and discussion, (c) supports and barriers for participation in sexual health education, and (d) children/youth value participation in their own care and promotion of their health. Results demonstrated that these children/youth have the capacities, interests, and values to actively participate in matters affecting their health and sexual health. Specific barriers and supports to sexual health education were identified. The study demonstrated how young people’s agency is socially mediated and can persist even when confronting significant barriers.