Cancer is a major cause of deaths in humans. Though there has been significant progress in cancer therapy, the limited efficacy and toxicities of current chemo- and radiotherapies have provided an impetus for the search of new therapeutics. A therapeutic approach, which uses viruses for the treatment of cancer termed, oncolytic virotherapy has recently emerged. Newcastle disease virus (NDV) is one such virus with an inherent oncolytic property. NDV causes a highly infectious disease in poultry worldwide. In humans it is reported to have oncolytic and immuno-stimulatory effects. It specifically replicates in tumour cells while sparing normal cells and cause oncolysis. For many years different strains of the NDV have been investigated for treatment of various human cancers. Recent advances in reverse genetics provided investigators the tools to produce recombinant NDV with improved oncolytic property.