Gay, bisexual, and other men who have sex with men (MSM) continue to have disproportionately high burdens of HIV infection in countries of low, middle, and high income in 2016. 4 years after publication of a Lancet Series on MSM and HIV, progress on reducing HIV incidence, expanding sustained access to treatment, and realising human rights gains for MSM remains markedly uneven and fraught with challenges. Incidence densities in MSM are unacceptably high in countries as diverse as China, Kenya, Thailand, the UK, and the USA, with substantial disparities observed in specific communities of MSM including young and minority populations. Although some settings have achieved sufficient coverage of treatment, pre-exposure prophylaxis (PrEP), and human rights protections for sexual and gender minorities to change the trajectory of the HIV epidemic in MSM, these are exceptions. The roll-out of PrEP has been notably slow and coverage nowhere near what will be required for full use of this new preventive approach. Despite progress on issues such as marriage equality and decriminalisation of same-sex behaviour in some countries, there has been a marked increase in anti-gay legislation in many countries, including Nigeria, Russia, and The Gambia. The global epidemic of HIV in MSM is ongoing, and global efforts to address it remain insufficient. This must change if we are ever to truly achieve an AIDS-free generation.