Young people – particularly girls and young women in sub-Saharan Africa – face significant challenges accessing sexual and reproductive health information and services. These challenges are shaped in part by sociocultural factors, including stigma. This paper presents findings from a qualitative study that explored the micro-level social process of stigma surrounding young people’s sexual and reproductive health in two communities in Tanzania. Respondents described an environment of pervasive stigma surrounding the sexual and reproductive health of unmarried young people. Stigma manifested itself in multiple forms, ranging from verbal harassment and social isolation to physical punishment by families, community members, peers and healthcare providers. Respondents perceived that stigma was a barrier to young people accessing sexual and reproductive health services and identified excessive questioning, scolding and requirements to bring sexual partners or parents to receive services at health facilities as obstacles to accessing care. The pervasiveness and complexities of stigma surrounding young people’s sexual and reproductive health in the two study communities and its potential consequences for health suggest both a need for care in using the term stigma as well as further studies on the feasibility of incorporating stigma-reduction strategies into young people’s sexual and reproductive health programmes.