The global biodiversity crisis necessitates exploring effective and sustainable conservation models beyond conventional, state-managed protected areas. Indigenous and Community-Conserved Areas (ICCAs), often rooted in Traditional Ecological Knowledge (TEK) and socio-cultural norms, represent a critical alternative. This paper presents a detailed academic examination of the Daikhow, the sacred groves of the Dimasa tribe in the Dima Hasao district of Assam, India, as a potent example of such a system. It argues that the Daikhow transcends its religious significance to function as a sophisticated, community-enforced mechanism for biodiversity conservation and ecosystem service provision. By weaving together, the Dimasa’s cosmology, social structures and subsistence strategies, the Daikhow system ensures the preservation of forest patches that act as vital refugia for flora and fauna in a fragmented landscape. This study first establishes a theoretical framework linking biocultural diversity, sacred natural sites and TEK. It then provides an ethnographic and geographic profile of the Dimasa people and their environment. The core of the paper analyses the socio-cultural, religious and ecological dimensions of the Daikhow, elucidating the taboos, rituals and institutional arrangements that govern its protection. Finally, it evaluates the tangible conservation outcomes while also addressing contemporary challenges posed by modernization, market integration and state policies. The paper concludes that the Dimasa Daikhow offers invaluable lessons for integrative conservation, underscoring the imperative to recognize, legally empower and support indigenous conservation initiatives as a cornerstone of global biodiversity strategies.