This paper discusses the influence of institutional environments on the formation and use of social capital in a particular field: the transfer of scientific and technological knowledge. It studies technology as well as research-based business creation as a means of knowledge transfer between academic research and business. In the case of the innovation system of Baden-Württemberg, characterized by its rich institutional landscape, the strong influence of institutions on the relational strategies of actors is shown. Professional relations are formed more readily where there are institutions guiding the actors’ behavior. The activities of technology transfer and the exploitation of new scientific knowledge are rooted in networks formed by well-institutionalized technology sectors (those of dealing with medium to high technology). In contrast, professional relationships develop less easily in weakly institutionalized sectors. The paper presents the example of the biotechnology sector, which has been the subject of a new policy of regional high technology cluster development. It shows the great difficulties involved in establishing such a strategy with a view to bringing research and business closer together and to intensifying exchanges between them. In spite of the existence of a strong and excellent research landscape in the region and despite the political and economic support provided to this initiative, its implementation requires a long-term perspective. JEL codes: M13, O14, O13, R11, L1, L2, Z13