The advent of gene silencing siRNA technology has created opportunities to develop therapeutics based on targeting the genomics of the disease state. Amongst the first applications of siRNA technology, antiviral applications have been quickly and extensively exploited allowing emergence of a range of antiviral therapeutic strategies. Patent activity has encompassed a range of the components required to utilize this technology ranging from the identification of susceptible genomic targets through to the development of vector systems to express the siRNA endogenously or the synthesis of stable RNA oligonucleotides for in vivo therapeutics. Indeed the primary focus of research effort in this area has been to overcome the challenge common to all of gene therapeutics - delivery of the oligonucleotide - to the diseased tissues and organs, sites of infection and/or sites of drug action. Here we survey the development of siRNA therapeutics both in terms of the range of virus species targeted and the strategic approaches employed. Our study illustrates features commonly observed in the field of nucleic acid drug development. While in vitro studies provide a broad range of molecules and molecular targets for potential therapeutics, the field is however severely limited in terms of safe, effective means to deliver the potential siRNA therapeutics in vivo, to the intracellular site of action.