Koi Herpesvirus (KHV) or Cyprinid herpesvirus-3 (CyHV-3) is considered among the most damaging viral diseases of common and koi carp aquaculture across the world. Koi herpes virus causes high mortalities, economic losses, and trade restrictions in aquaculture industry. One of the major problems related to KHV is its capability to cause latent infection in surviving fishes. In latent infection, the virus exists in hiding within the host organisms without showing any clinical signs; mainly within leukocytes and nervous tissues. Latently infected fishes serve as silent carrier of the virus that can be reactivated under certain stress conditions such as temperature change, transportation, crowding, and poor water conditions. Reactivation causes shedding of virus from latently infected fish and further spread of virus among clinically healthy fish populations. Research has shown that KHV DNA can be detected in blood leukocytes and many other organs even in healthy carp. Temperature changes have been reported as one of the most important factors that induce viral shedding from latently infected fishes. The detection of latent infection is very difficult due to presence of extremely low numbers of viral DNA during latency stage. PCR and Realtime PCR have been used successfully to detect latent KHV infection. It is necessary to have good surveillance, biosecurity measures, stress reduction, and periodic screening in order to avoid silent transmission of the virus. It is vital to understand the process of latent infection and reactivation for sustainable carp farming.