This paper attempts to explain decision-making structures in Swiss politics. Decision-making structures describe the relations between collective actors collaborating and fighting for influence in a policy network and are defined by two main dimensions, which are power and conflict. For the explanation of decision-making structures, the paper relies on factors such as Europeanization, media presence, federalism, the pre-parliamentary phase and the referendum. I assume that these different factors interact with each other when they influence the decision-making structure. In order to assess the importance of these factors, the paper compares the 11 most important decision-making processes in Switzerland between 2001 and 2006. The analysis relies on an innovative integration of two methods. In a first step, I apply Social Network Analysis to describe the two dimensions of decision-making structures. In a second step, in order to detect the different combinations of causes which lead to different structures, the 11 cases are compared by a Qualitative-Comparative Analysis (QCA). The results suggest that all five factors are important to understand decision-making structures and that equifinality and conjunctural causation are at work.