Puerto Rico is aging faster than almost any other country, with 2020 estimates placing the proportion of adults over 65 as the tenth highest in the world. Unlike most places, aging in Puerto Rico is driven both by (a) the culmination of prolonged trends in fertility and mortality, and by (b) the high levels of emigration of working-age adults, which contribute directly (leaving young people) and indirectly (reducing births) to the rate of population aging. This article provides an overview of the main issues related to population aging in Puerto Rico. Policymakers and government leaders must plan for the unconventional aging of Puerto Rico's population, which will aggravate traditional concerns about the sustainability of government services and long-term economic prospects. Concerns also arise related to the reduction of social support networks and their impact on the dynamics of care and the implications for health. Puerto Rico's unique history and its political relationship with the United States present challenges and benefits for its aging population. Research on aging in Puerto Rico and public health policies must be adapted to the needs of the country's aging society.