Making use of the scarce and limited population surveys available in Chile, the evolution of age at first intercourse and the use of contraceptives is described, both in terms of magnitude and social and gender inequality. Age at first intercourse has become younger, primarily premarital, and gender differences have narrowed. The use of contraceptives at first sexual intercourse has increased, although it continues to be lower than in developed countries 20 years ago. Social inequality in the use of contraceptives at first intercourse is more pronounced than inequality in first intercourse itself. This underlines the priority of universalizing access to contraceptives, starting with the first sexual encounter, so that each adolescent can make their decision about contraceptives freely, consciously and well informed, without additional restrictions to those that are legally established.