Changing climatic scenarios accompanied with harsh ecological conditions are forcing various groups of organisms to evolve and adapt in different dimensions. Predominantly in the field of agriculture and crop science, several categories of new pests along with diseases are emerging voraciously causing havoc and causing panic-stricken situations for the farmers. Among the pests, nematode is one of the unnoticed categories contributing significantly to economic loss to the farmers. Due to monotonous crop protection practices in some of the areas as well as drastic changes in the environmental factors, new species of nematode are evolving and attacking economically important crop species. For that, we have to understand the pattern of feeding, oviposition site, life cycle, host searching behaviour, parasitic stages and susceptible host stage for attacking in order to form proper management practices. For understanding its mechanisms and behaviour, our prime concern will be its identification and taxonomic classification by various conventional as well as molecular approaches. Molecular approaches are turning out to be a useful and vigorous tool for the identification of the phylum Nematoda replacing conventional ones.