分子病毒学是1950年代分子生物学兴起以来将分子生物学方法运用于病毒学而形成的一门学科。1960年代以来，DNA病毒和RNA病毒的复制机制都得以阐明，一类亚病毒被发现；创建了绝大多数病毒基因组的无性繁殖系；某些病毒基因的结构与功能的关系以及一些病毒的基因表达调控原理被发现。病毒基因组学、病毒免疫学都得以长足进展。病毒的诊断和预防都有了一系列进步。 其方向主要包括:

Molecular virology is the study of viruses on a molecular level. Viruses are submicroscopic parasites that replicate inside host cells. They are able to successfully infect and parasitize all kinds of life forms- from microorganisms to plants and animals- and as a result viruses have more biological diversity than the rest of the bacterial, plant, and animal kingdoms combined. Studying this diversity is the key to a better understanding of how viruses interact with their hosts, replicate inside them, and cause diseases.