Introduction Despite young people being a key population for HIV prevention, the HIV epidemic amongst young Brazilians is perceived to be growing. We therefore reviewed all published literature on HIV prevalence and risk factors for HIV infection amongst 10–25 year olds in Brazil.

Methods We searched Embase, LILACS, PsycINFO, PubMed and Web of Science for studies published up to May 2015 and analysed reference lists of relevant studies. We included peer-reviewed studies from any time in the HIV epidemic which provided estimates specific to ages 10–25 (or some subset of this age range) for Brazilians on either: (a) HIV prevalence or incidence; or (b) the association between HIV and socio-demographic or behavioural risk factors.

Results 37 studies in 36 publications met the inclusion criteria: 33 cross-sectional, two case-control, two cohort. Three studies analysed national data. 31 studies provided HIV prevalence estimates, largely for six population subgroups: Counselling and Testing Centre attendees; blood donors; pregnant women; institutional individuals; men-who-have-sex-with-men (MSM) and female sex workers (FSW); two provided HIV incidence estimates. Ten studies showed HIV status to be associated with a wide range of risk factors, including age, sexual and reproductive history, infection history, substance use, geography, marital status, mental health and socioeconomic status.

Conclusion Few published studies have examined HIV amongst young people in Brazil, and those published have been largely cross-sectional and focused on traditional risk groups and the south of the country. Despite these limitations, the literature shows raised HIV prevalence amongst MSM and FSW, as well as amongst those using drugs. Time trends are harder to identify, although rates appear to be falling for pregnant women, possibly reversing an earlier de-masculinization of the epidemic. Improved surveillance of HIV incidence, prevalence and risk factors is a key component of efforts to eliminate HIV in Brazil.