SETTING: Western Cape Province, South Africa.OBJECTIVES: To characterise tuberculosis (TB) epidemiology, disease presentation and treatment outcomes among adolescents (age 10-19 years) and young adults (age 20-24 years) in the Western Cape.DESIGN: A retrospective, cross-sectional review of routine patient-level data from the Electronic TB Register (ETR.Net) for 2013. Site of TB disease, human immunodeficiency virus (HIV) status and TB treatment outcomes were analysed by 5-year age groups (<5, 5-9, 10-14, 15-19, 20-24 and 25 years of age). TB notification rates were calculated using census data.RESULTS: Adolescents and young adults comprised 18.0% of all new TB notifications in 2013. The notification rate was 141 TB cases/100 000 person-years (py) among 10-14 year olds, 418/100 000 py among 15-19 year olds and 627/100 000 py among 20-24 year olds. HIV prevalence among TB patients was 10.9% in 10-14 year olds, 8.8% in 15-19 year olds and 27.2% in 20-24 year olds. Older adolescents (age 15-19 years) and young adults (age 20-24 years) with HIV co-infection had poor treatment outcomes: 15.6% discontinued treatment prematurely and 4.0% died.CONCLUSIONS: Young people in the Western Cape suffer a substantial burden of TB, and those with TB-HIV co-infection are at high risk of treatment discontinuation.