BACKGROUND:TB preventive therapy (TPT) is critical for ending TB, yet implementation remains poor. With new global guidelines expanding TPT eligibility and regimens, we aimed to understand TPT preferences among children, adolescents and caregivers.METHODS:We undertook a discrete choice experiment among 131 children, 170 adolescents and 173 caregivers, and conducted 17 in-depth interviews in 25 clinics in Cape Town, South Africa. The design included attributes for location, waiting time, treatment duration, dosing frequency, formulation/size, side effects, packaging and taste. Mixed-effects logistic regression models were used for analysis.RESULTS:Among children and caregivers, the number and size of pills, taste and side effects were important drivers of preferences. Among adolescents and caregivers, clinic waiting times and side effects were significant drivers of preferences. Adolescents expressed concerns about being stigmatised, and preferred services from local clinics to services delivered in the community. Dosing frequency and treatment duration were only significant drivers of choice among adolescents, and only if linked to fewer clinic visits.CONCLUSIONS:Introducing shorter TPT regimens in isolation without consideration of preferences and health services may not have the desired effect on uptake and completion. Developing TPT delivery models and formulations that align with preferences must be prioritised.