In this section, cryopreservation of fish genetic resources, which is one of the important applications to ensure the sustainability of genetic resources of freshwater fish species, is discussed. At the same time, information is provided about the possible sources of contamination that may be encountered during cryopreservation applications. In this context, the results of sperm, egg, and embryo cryopreservation studies of fish and their success and failure in applications were evaluated in addition to the process from past to present. Information is given about the contamination that may develop depending on the applications in the process of cryopreservation and dissolving processes, as well as the studies carried out to eliminate extracellular disease agents. In the section, in addition to the evaluation of the results of scientific studies, commercial companies that commercially carry out gamete cryopreservation applications are also included. The contamination that may develop depending on the applications in the process of cryopreservation and thawing processes, as well as the studies carried out to eliminate extracellular disease agents are mentioned.