This book on administrative law in Aotearoa New Zealand fills a gap with its fresh scholarly account of the law in this area, focusing on analysis of structures and principles. It identifies underlying tensions between competing objectives and outlines current trends and debates. It includes chapters on administrative justice, and throughout promotes an awareness of wider administrative law beyond judicial review. Given the recent recognition of tikanga - Maori customary law - as part of the laws of Aotearoa New Zealand, this book also offers tentative explorations of the roles tikanga may come to play in administrative law. The book is suitable for use in university courses, especially in specialist administrative law courses. It is also addressed to judges, officials and practitioners seeking to deepen their understanding of this area of law; to academic audiences around the common law world; and to policy makers designing or evaluating administrative regimes.