The study examined the implementation of Relationships and Sexuality Education (RSE) in Irish postprimary schools. This research is the most comprehensive study of relationships and sexuality education conducted in Ireland to date. This study sought to capture the factors that have helped and hindered the implementation of RSE since the programme was first introduced to post-primary schools in 1995. The findings of this study are vital to informing future educational policy with regard to the teaching and resourcing of RSE in second-level schools. The research examines RSE implementation levels, identifies facilitators of and barriers to RSE implementation and delivery, and also describes participants' views on the impact of societal change on the RSE curriculum since the programme was formally introduced in 1995. It provides an important voice, not only for education and health and community professionals, but also for principals, teachers and, notably, parents and students in school communities.