The German expression “Begleitforschung” is a concept with multiple meanings that are the subject of controversial discussion, and has no equivalent in English. It could be directly translated as “accompanying research”, and covers research activities which are commonly covered by the abbreviations EHS (Environment, Health, and Safety) and ELSI (ethical, legal, and social issues). Although there is no direct translation, research with the purpose of “Begleitforschung” is financed and carried out in almost all industrialised countries. In this dossier the variety of the meanings and uses of “accompanying research” is elaborated. As the outcome of this analysis, it is argued that the concept only makes sense in a particular political context and cannot be deduced from any disciplinary perspective. It is a relational notion which seeks to express the ratio between the efforts applied to R&D and the efforts made to explore and analyse social aspects which could be related to this technology. Despite practical difficulties, due to the fact that a general criterion (such as origin of funding) is not sufficient, it is only possible to decide on a case by case basis whether or not a research activity can be identified as “accompanying research”. The dossier ends with a plea for a differentiated use of the notion and for an explicit specification of what kind of research is meant.