Fish disease is a major constraint in sustainable growth for global aquaculture. I nfectious bacteria causing significant economic losses are only treated by antibiotics. Excessive antibiotics use negatively influences the surrounding environment and enables bacterium to be resistant to antibiotics. Therefore, bacteriophages, natural enemies to specific bacteria, have been paid attention to aquaculture as an alternative to antibiotics . This paper will encourage a reduction in antibiotic use in fish farming by using the natural occurring bacteriophages to combat bacteria. However, marketability of bacteriophages is unknown since seafood products treated with bacteriophages are not commercially available yet. T hough there are studies about consumer preferences for seafood attributes in some European countries, their main focus is not how fish diseases are treated, especially by bacteriophages. Thus, this study investigates the marketability of seafood farmed with bacteriophages by applying a discrete choice experiment (DCE) and Contingent Valuation (CV) to estimate the willingness-to-pay for rainbow trout fillet treated with bacteriophages in Denmark. This research contributes to revealing extra amounts of money consumers are willing to pay for avoiding antibiotics and making bacteriophages commercially available in the aquaculture industry. We believe this study promotes a more sustainable future for aquaculture by reducing the use of antibiotics.