Fish infecting viruses are rapidly increasing with identification and classification of new emerging viruses in aquaculture. Treatment and use of chemotherapeutics in aquaculture is often limited in fish infecting viruses. Unlike human viruses, it is difficult to treat fish viruses because of its wide survival range in different physio-chemical conditions and varied geographic conditions. Thus in general no approved treatments are available for fish viruses, scientists majorly rely on vaccination therapy which is still ongoing and several vaccines have been developed in United States and other nations. For the vaccination and treatment related studies in fish viruses there is a need of understanding the morphology and possible entry mechanisms of the major fish infecting viruses which has been discussed under this review.