Viral diseases are not only responsible for health related issues but also exert pressure on the State economy. Tropical and subtropical countries have more prevalence of virus associated pathological conditions such as chickenpox, adenovirus related infections, dengue, chickengunya, infectious mononucleosis, etc. Treatment options with effective antiviral drugs are limited and are unfortunately not free from undesirable effects. The Asian Green Mussel, Perna viridis (Linn.) (Mytilidae) are not only important for their evolutionary significance, high caloric index, ecological role in the sequestration of environmental pollutants especially heavy metals, but also are potential source for extraction of therapeutic and bioactive compounds. On the other hand, generally in bivalves, virus mediated mortality is not uncommon. In this study, we made a maiden attempt of exploring DNAse like bioactivity for natural non-protenacious compound(s) extracted from P. viridis. Crude Methanol Extract (CME) of soft tissue of P. viridis and subsequently its partially purified component (PPC) possess exceptional ability to degrade indiscriminately both low and high molecular weight DNAs. In vitro digestions for1, 2 and 3 h with CME and PPC were found to be comparable to commercial (Sigma-Aldrich) enzyme, DNase I. Bioactive assays conducted to evaluate antimicrobial property, have shown that CME and PPC exclusively inhibit viral propagation. Nonetheless, CME & PPC have no effect on the propagation of bacteria (0 mm ZOI). These results indicate the possibility of a source of potential antiviral drug against DNA Group I viruses. Although our study does not provide any data to correlate to any physiological functions of these substances but provides a clue towards an important role in the biology of mussels. Any conclusion at this stage is premature. However, taking into consideration the significantly high virus mediated mortality in bivalves and the antiviral bioactivity of these substances, it appears that mussels have evolved some mechanisms to counteract some viruses.