The Marine Directors of the European Union (EU), Acceding Countries, Candidate Countries and EFTA Countries have jointly developed a common strategy for supporting the implementation of the Directive 2008/56/EC, “the Marine Strategy Framework Directive” (MSFD). The main aim of this strategy is to allow a coherent and harmonious implementation of the Directive. Focus is on methodological questions related to a common understanding of the technical and scientific implications of the Marine Strategy Framework Directive. In particular, one of the objectives of the strategy is the development of non-legally binding and practical documents, such as this technical guidance on monitoring for the MSFD. These documents are targeted to those experts who are directly or indirectly implementing the MSFD in the marine regions. The document has been prepared by the Joint Research Centre of the European Commission (JRC) with the contribution of experts from Member States, Regional Seas Conventions and ICES and following consultation of the Working Group on Good Environmental Status.