In this paper a protocol based on the application of Buffodine® disinfectant and a mix of antibacterials for obtaining rainbow trout (Oncorhynchus mykiss) axenic fingerlings is described. This allowed to obtain and maintain axenic trout fingerlings for a period of 26 days. This time allow to achieve a gnotobiotic organism, a fundamental tool in studies of the understanding bacteria-host interaction or host-parasite interaction.