Background HIV remained to be a major public health problem affecting the lives and livelihood of many in Sub-Saharan Africa (SSA). Young people (15–24 years) accounted for 42% of new HIV infections in people aged 15 years and older; and about 80% of them live in SSA. Knowing HIV status among young people can be one of key strategies in reducing transmission. Knowing HIV status is associated with increased safe sex practices, decreased number of partners and early/timely access to ART in HIV-positive. In Tanzania, only 54% of females and 34% of males aged 15 -24 years have ever been tested HIV with limited information regarding factors associated with testing among young people.

Methods This was a secondary analysis of Tanzania HIV and Malaria Indicator Surveys data (THMIS) conducted in 2011–12. Descriptive statistics, bivariate and regression modelling of survey data were used to determine predictors of HIV testing among young people in Tanzania.

Results Prevalence of HIV among young people is 2.0% (young women 3% vs. young men 1%). Nearly half of all young people have ever tested for HIV (44.9%). HIV testing was associated with older age (20–24 years) [AOR = 3.0, 95% CI: 2.4–3.6]; female gender [AOR = 2.9, 95% CI: 2.4–3.5]; currently married [AOR = 3.0, 95% CI: 2.3–3.8]; formerly married [AOR = 2.4, 95% CI: 1.6–3.6]; primary education [AOR = 1.8, 95% CI: 1.3–2.5]; secondary education [AOR = 3.5, 95% CI: 2.4–5.1]; living in urban areas [AOR = 1.4, 95% CI: 1.2–1.7] and having stigmatising attitudes towards HIV [AOR = 1.2, 95% CI: 1.0–1.4].

Conclusion HIV prevalence in young women is three times higher than in young men. In this high HI-prevalence setting almost half of young people have not tested for HIV. Provision of information and sensitisation among young people on HIV testing should focus on young people who are single, uneducated and living in rural areas.