Abstract The study analyses the economic viability of the mesopelagic fish exploitation. Operating characteristics of the selected bottom-trawl fleet operating in the Bay of Biscay were analysed on a trip basis, from the technical, financial and market perspectives. The results show that, while this activity is technically possible, it cannot be considered a viable financial alternative to the existing commercial fisheries. However, the landing obligation of the European Union Common Fisheries Policy, to become fully operational in 2019, provides an economic incentive in the form of alternative trips. The fishing effort is to be limited by this regulation. Thus, the discouraging opportunity costs of fishing mesopelagic species might be alleviated by the effort limitation. Additionally, the existing markets might expand, and new opportunities for commercial fisheries of mesopelagic species might be created. The sustainability of exploitation and its impact on the ecosystem services associated with these species should be considered in their management.