AbstractHistorical and modern data on the taxonomic status, external morphology, distribution features, biology, economic importance, history of fishing, conservation status, and protection measures for the Caspian lamprey Caspiomyzon wagneri are presented. The Caspian lamprey is an endemic species and the only anadromous lamprey in the Caspian Sea basin. The abundance of this species has declined everywhere; as a result, the species nowadays is on the verge of extinction. Being an important target of fishing in the past, the Caspian lamprey has completely lost its economic importance. It is subject to serious threats of an anthropogenic nature. Constructing of locks and dams without fish passages that prevent spawning migrations, water pollution, dredging and mining of sand and gravel leading to the destruction of habitats and spawning grounds, poaching and lack of legal protection mechanisms are the main threats for this lamprey species.