Sexual and reproductive health (SRH) education for young people is a challenge for national health systems in low-and middle-income countries. This study analysed SRH education among adolescents in a low-income neighbourhood of Brazil from the perspectives of young people themselves, primary healthcare providers, and school teachers. Using semi-structured interviews, data were collected from twelve informants aged 15-20 years, eight health professionals, and nine teachers. Interviews were analysed using the ecological framework (i.e. with a focus on individual, structural and programmatic levels). At the individual level, there was a marked lack of discussion about SRH in the family, especially with parents. As a result, young people sought information from relatives of a similar age, the Internet and social media. Racism on the part of some teachers was identified as a structural-level constraint, and lack of dialogue between the health and education sectors was a programmatic barrier. Schools were seen as propitious settings for SRH education, and joint action by health providers and teachers could be beneficial for the promotion of SRH among young people in schools.