Te Kotahitanga is a kaupapa Māori research and professional development project currently operating in 33 mainstream secondary schools. This project was developed in response to the ongoing problem of educational disparities for Māori students, one of New Zealand's most pressing educational issues. From initial conversations with Maori students, their families, their principals and their teachers about what constituted effective teaching understandings and practice for Maori students, we developed an Effective Teaching Profile. This Profile is central to the professional development work that has been implemented in Te Kotahitanga schools with notable increases in a range of outcomes for Maori students.