The Salud Mesoamérica Initiative (SMI) focuses on reducing inequalities in maternal and child health in Mesoamerica. This dataset is the product of an SMI impact evaluation. It includes results of a baseline school survey conducted in the provinces of Limón and Puntarenas in Costa Rico. The survey was conducted in a randomly selected sample of 41 secondary schools: high schools, technical schools, and night schools. The target sample for the survey was 1,000 students. Within each school, all sections in 7th-11th grades were eligible to be selected for the survey, and a section from each eligible grade was randomly selected to participate. Students completed a self-administered questionnaire which captured knowledge, attitudes, and behaviors related to the sexual and reproductive health of school students, as well as contact with reproductive health services.