This early-release guideline makes available two key recommendations that were developed during the revision process in 2015. First, antiretroviral therapy (ART) should be initiated in everyone living with HIV at any CD4 cell count. Second, the use of daily oral pre-exposure prophylaxis (PrEP) is recommended as a prevention choice for people at substantial risk of HIV infection as part of combination prevention approaches. The first of these recommendations is based on evidence from clinical trials and observational studies released since 2013 showing that earlier use of ART results in better clinical outcomes for people living with HIV compared with delayed treatment. The second recommendation is based on clinical trial results confirming the efficacy of the ARV drug tenofovir for use as PrEP to prevent people from acquiring HIV in a wide variety of settings and populations. The recommendations in this guideline will form part of the revised consolidated guidelines on the use of ARV drugs for treating and preventing HIV infection to be published by WHO in 2016. The full update of the guidelines will consist of comprehensive clinical recommendations together with revised operational and service delivery guidance to support implementation.