Fungal pathogenic populations such as Sclerotinia, Rhizoctonia and Fusarium are ubiquitous and have broad range of host enabling them to cause a severe infection resulting in huge yield losses. Albeit the various tactics such as cultural, mechanical implemented to counteract the havoc, it still creates a formidable challenge to the researchers to keep the pathogenic population below threshold. From Eco-friendly sustenance perspective, Biological control can play a vital role in combination along with the other efficient tactics. In field condition various strains are available having two characters namely virulent and hypovirulent, the latter may exhibit hypovirulent nature genetically or due to the invasion of mycoviruses becomes hypovirulent. In both the cases are of interest to the researchers in studying the biological control exhibited by the mycoviruses. The biocontrol agents include Mycoviruses, which plays a significant role in infecting the virulent fungal pathogen by reducing their virulence giving to a phenomenon known as Hypovirulence. Their genome consist of mostly dsRNA and others include +ssRNA, -ssRNA and dsDNA. These studies in fungal and viral interaction can lead to the development of novel biological control strategies and help us to explore upto the molecular level.