Chile has undergone a profound demographic transition over the past century. The country has moved from a pattern characterized by high fertility and mortality to one marked by exceptionally low fertility, low mortality, and rapid population ageing. The decline in infant and maternal mortality was achieved through a combination of improvements in living conditions, nutrition, sanitation, healthcare, maternal and child health services, and the development of a national health system. The implementation of a national family-planning policy in the 1960s represented an important milestone in Chile's reproductive health history, particularly in addressing the high maternal mortality associated with unsafe abortion and high parity. Fertility subsequently declined substantially, in parallel with improvements in female education, participation in the workforce, urbanization, socioeconomic development, and access to reproductive healthcare. Chile has now entered a new demographic phase. Provisional official vital statistics for 2025 report 146,446 live births and a total fertility rate of 0.99 live births per woman, while infant mortality has declined to 5.8 deaths per 1,000 live births. These figures place Chile among countries experiencing very low fertility. This new demographic reality presents challenges for population ageing, the future workforce, social protection, healthcare, and family policy. The objective should not be to reverse the advances in reproductive autonomy achieved over previous decades, but to develop social policies that enable women and couples who wish to have children to do so without disproportionate economic, occupational, or social costs.