The aim of the study is to present a detailed set of specific indicators, methods of evaluation and units of measurement for the welfare assessment of farmed European sea bass, Dicentrarchus labrax. The study provides the user with prerequisites for welfare risk assessment, including risk tolerance, definition of uncertainty level, identification of relevant factors and elements of a risk management system. Finally, the study proposes a welfare assessment scheme, based on the welfare metrics of each specific welfare indicator, for on-growing fish that can be readily interpreted by all stakeholders and regulatory authorities involved in aquaculture.