 The Kia Tamata Pi study is a cluster randomized controlled trial that evaluates the effectiveness of an oral language intervention, enrich, and a self-regulation intervention, engage, with early childhood teachers and parents for children's oral language, self-regulation, and academic functioning. The study involves approximately 140 early childhood centres in New Zealand, with children assessed at baseline at age 1.5 years and approximately every nine months to age 5, and academic performance at age 6. Teacher-child interactions will also be videotaped each year in a subset of the centres, and children's brain and behaviour development and parent-child interactions will be assessed every six months to age six years in a subgroup of volunteers. The study has been approved by the University of Otago Human Ethics Committee and will disseminate results in international and national peer-reviewed academic journals and communicate with local, national, and international organisations serving early childhood teachers, parents, and young children. This article was authored by Charles Nelson, Ran Wei, Richie Poulton, and others.