This article examines the access to Comprehensive Sexual Education (CSE) among secondary school students in Argentina, based on data from a national survey conducted with students and school principals. Drawing on responses to the CSE module of the 2022 Aprender Assessment (195.804 participants), the study characterizes the students’ exposure to CSE. The evaluation considers four analytical dimensions: the relevance, the universality, the comprehensiveness, and the cross-curricular integration of the contents received. The results reveal a gap between students’ widespread acknowledgment of the importance of CSE and its effective implementation, with disparities observed by sex, educational background of the household, and region. Moreover, there is a predominance of approaches focused on biology and health, to the detriment of dimensions related to affectivity, diversity, and rights.