Adat Iban are Indigenous law of the Iban people of Sarawak, Malaysia. This dissertation explores the wisdom of Adat Iban and examines whether the Adat and the underlying wisdom are living Adat. Currently, the interpretation, application, and enforcement of the Adat are basically following the Iban ancestors’ practices and complying with spiritual obligations. This practice provides very little legal reasoning which obscures the rationales and wisdom of Adat. Under such situation, the flux of socio-economic and political developments and social changes that have been taking place in the Iban communities impinges the relevance and significance of Adat in the regulation of social relations of the communities. This study presents a reinterpretation and/or re-evaluation of Adat Iban to elucidate the rationales and wisdom of Adat Iban. This approach could provide legal reasonings which could rejuvenate the relevance of Adat and make Adat to become more comprehensible law of general application to the changing Iban communities. “Wisdom” encompasses Iban autochthonous knowledge, ideas, experiences, judgements, and spiritual principle that evolved into Adat. Wisdom is the quality that enables an Adat to be utilised to bring about beneficial or noble purpose, or justice. The study contends that there is wisdom in most Adat Iban. However, the social changes and modernisation that are taking place in most Iban communities raise the question of whether the Adat and the underlying wisdom are living Adat. A living Adat is one that is dynamic and flexible and constantly adjusting and adapting to the new or changing social situations. This study concludes that most Adat Iban have the potential to be living Adat and continue to be relevant for the regulation of Iban communities. However, the survival, development, and continuing relevance of Adat Iban depend on the Iban. / Graduate / 2021-11-18