This report presents the findings from a research project on curriculum integration in New Zealand schools, carried out by NZCER in 2018-19. The purpose of the research was to explore teachers' rationales for curriculum integration; the approaches and practices used to integrate curriculum; and the learning opportunities such approaches provide for students. Research questions include the following: (1) What sorts of outcomes do teachers envisage when they integrate subjects (i.e., what are their purposes for doing so)?; (2) What sorts of topics are used to integrate learning across learning areas?; (3) How is integration achieved in practice? (For example, how are different learning areas differentiated and/or juxtaposed?); (4) What is taught about the knowledge-building (epistemic) processes of each discipline?; and (5) What learning opportunities does curriculum integration afford students, and do the opportunities differ for different groups of students, including those traditionally underserved by the education system?