The origins and genomic affinities of various tribal populations of India are of considerable contemporary interest. In this study, we have investigated relationships among five tribal groups inhabiting the north-eastern, eastern and sub-Himalayan regions of India. DNA samples have been analysed in respect of 25 polymorphic loci, based on which genetic affinities have been estimated. The interesting findings of this study are (i) the Tibeto-Burman speaking, morphologically Mongoloid, tribal groups of India are not genetically very homogeneous, and (ii) the Tharu, a group inhabiting the sub-Himalayan region, may indeed have undergone considerable admixture as has been postulated by some anthropologists.