North-East India, which falls under the Indian Eastern Himalayan region and forms part of two global biodiversity hotspots, is well-known for its rich diversity of flora, fauna, cultures, and traditional knowledge systems. Agriculture is the main occupation of the communities living in this mountainous region supplemented by the utilization of wild useful species from the nearby forests. Traditional agriculture in North-East India follows a mixed cropping pattern through multi-cropping, crop rotation, and use of multipurpose nitrogen (N)-fixing trees, along with protection of semi-domesticated and wild biodiversity, including medicinal plants, wild edible fruits and vegetables, fodder plants and other useful species. Presently, there has been a gradual shift from subsistence cultivation to commercial agriculture driven by market forces and modernization, leading to a transition from traditional to intensive agriculture and monoculture of cash crops. This has resulted in reduced cultivation of local crop varieties and the disappearance of the associated traditional ecological knowledge (TEK). Therefore, the present study attempts to review the contribution of traditional agricultural practices to agrobiodiversity conservation and sustainable natural resource management. Traditional practices such as shifting (Jhum) cultivation systems, bamboo-drip irrigation, paddy-cum-fish cultivation, traditional agroforestry systems of different Indigenous communities residing in different states of North-East India were mentioned in this review. It is undeniable that TEK was developed by communities through many centuries by trial-and-error methods to conform to the local climate, topography, ecology, and socio-cultural relevance to the concerned Indigenous communities. This knowledge, therefore, has a great scope for improvement by integration with scientific knowledge for transforming into sustainable agricultural systems in the face of climate change adaptation and mitigation of the vulnerable mountain communities of the Himalayan region.