Project networks are an organizational form of production and exchange among functionally interdependent but legally autonomous firms and individuals. Although these networks are of limited duration, co-ordination of actors and activities takes place with respect to past experiences and future expectations. Project networks depend on supportive institutions in the surrounding organizational field to provide the regulative and normative resources within which practices are given meaning. In this paper, we explore the role of 'institutional thickness' for the performance of project networks in television content production in two media regions in Germany. We use GIDDENS', 1984, structuration perspective, to emphasize the dynamics and ambiguities of institutional processes. The analysis suggests that the two media regions differ in institutional thickness in ways which explain, at least in part, differences in the growth and viability of project networks.