Reviewing the research in the field of oncolytic virus therapy (OVT) of the past two decades, it is inspiring to see the enormous amount of success accomplished by the scholars of this innovative therapeutic technique. Though the experimental trials have been ongoing from 1990s, however, it took a leap forward with approval of the clinical trials in China, 2005. The world's first oncolytic virus to be approved by their government was adenovirus (with E1B 55K gene deletion) for head and neck cancer therapy along with chemotherapy.