The Marine Strategy Framework Directive (MSFD) requires EU member states (MS) to develop and implement marine strategies containing programs of measures to protect and preserve the marine environment. Prior to their implementation, impact assessments, including Cost-Benefit-Analyses (CBA), need to be carried out. While the costs of introducing such measures are often relatively easy to determine, the economic valuation of the benefits derived from environmental improvements is much more challenging, particularly in the marine context. Still, it remains an important prerequisite for conducting CBA. The aim of this paper is to evaluate to what extent benefits can be quantified for use in CBA focusing on the German marine waters. The results indicate that there are still considerable gaps in the scientific knowledge about many of the pressures mentioned in the MSFD. Moreover, few economic studies exist that evaluate the benefits of marine protection measures, and many of them are not applicable in the German context. In addition, there is the risk that some benefits accruing from marine protection measures are systematically omitted in CBA. This raises the question to what extent comprehensive CBAs as required by the MSFD are possible in Germany, but also in other EU MS.