Ecosystem services have constituted a highly discussed topic especially since the Millennium Ecosystem Assessment. This is in particular valid for the literature in environmental sciences and related economic sciences. The topic has gained less attention in other social sciences and up until now legal scholars have hardly taken up the issue for an in-depth analysis. Moreover in the legal practice the term has not played any substantial role apart from its inclusion in soft law documents that lack concrete and effective implementation including enforcement mechanisms. This paper addresses the issue of inclusion of the term ecosystem services in legislative documents with such mechanisms. Starting from a neutral position, it discusses the potentials and pitfalls of such an inclusion in the light of the ongoing contradictory discourse about the concept of ecosystem services. This is done by an in-depth review of existing academic literature as well as by empirical quantitative research on EU-law, and by a case study. This case study concerns the on-going assessment of the inclusion of the term ecosystem services into a binding legal act of regional integration on the example of the Regulation of the European Union (EU) on Invasive Alien species. The analysis also covers primary data derived from questionnaires and interviews completed by a wide range of stakeholders from two member states of the EU. The results provide an overview of opportunities and challenges of the inclusion of the term ecosystem services in this particular context of binding and enforceable regional integration law based also on a practical example. The ongoing implementation of this EU-Regulation can provide a blueprint for similar situations of coordinated legislative procedures between different levels of law-making and its implementation including enforcement. These situations can occur beyond a nation's borders or within. Similar research has not been implemented yet according to the knowledge of the authors. Therefore, the results of this contribution provide innovative insights into an ongoing legislative procedure with binding rules on ecosystem services and useful hinds for similar other prospective attempts worldwide.