These consolidated guidelines on HIV prevention, testing, treatment, service delivery and monitoring bring together existing and new clinical and programmatic recommendations across different ages, populations and settings, bringing together all relevant WHO guidance on HIV produced since 2016. It serves as an update to the previous edition of the consolidated guidelines on HIV. These guidelines continue to be structured along the continuum of HIV care. Information on new combination prevention approaches, HIV testing, ARV regimens and treatment monitoring are included. There is a new chapter on advanced HIV disease that integrates updated guidance on the management of important HIV comorbidities, including cryptococcal disease, histoplasmosis and tuberculosis. The chapter on general HIV care, contains a new section on palliative care and pain management, and up to date information on treatment of several neglected tropical diseases, such as visceral leishmaniasis and Buruli ulcer. New recommendations for screening and treating of cervical pre-cancer lesions in women living with HIV are also addressed in this chapter. Guidance on service delivery was expanded to help the implementation and strengthening the HIV care cascade. Importantly, this guidance emphasizes the need for differentiated approaches to care for people who are established on ART, such as reduced frequency of clinic visits, use of multi-month drug dispensing and implementation of community ART distribution. The adoption of these efficiencies is essential to improve the quality of care of people receiving treatment and reduce the burden on health facilities, particularly in resource limited settings.