An analytical cohort study is proposed to characterise genital human papillomavirus (HPV) acquisition in adolescent girls after sexual debut. Information of this kind is lacking in sub-Saharan Africa where the majority of the burden of HPV related diseases lies. Specifically this study will describe type specific incidence of HPV and sexual behavioural and demographic factors associated with this. Evaluation of risk factors associated with HPV persistence, clearance and re-infection will be undertaken. 325 participants will be recruited from the control arm of a school-based vaccination trial and will be followed up 3 monthly for a total of 18 months and asked to provide self-administered swabs. These will be tested for 13 high-risk and 24 low-risk genotypes. The study will be based in Tanzania, a country with an extremely high burden of cervical cancer and mortality and will provide data for modelling HPV infection and informing vaccination and screening programmes.