PURPOSE OF REVIEW: People who inject drugs (PWID), sex workers, and MSM simultaneously bear a high burden of HIV and stigma and discrimination. The purpose of this review was to summarize recent information about the understanding of the HIV care cascade among PWID, sex workers, and MSM populations around the globe. RECENT FINDINGS: A review of the published literature relating to the care cascade in these three key populations was conducted. Data on the care cascade among key populations are sparse, particularly for PWID and sex workers. In the 12 countries in which a study or report of the care cascade was available stratified by these populations, all three populations have care cascade outcomes that are far below the 90-90-90 target set by the Joint United Nations Programme on HIV/AIDS (UNAIDS) for 2020. Culturally tailored interventions, including colocation of services and peer navigators, can improve care cascade outcomes among key populations. SUMMARY: Key populations' care cascade outcomes must be included in international reporting metrics to expand cascade data for these groups. Improving care cascade outcomes in these key populations through culturally tailored interventions should be a priority in the coming years.