Recently in supply management research, the power theme has gained growing interest. The analysis of power in the context of dyadic relationship between a buyer and supplier has been criticized for having a limited viewpoint because it fails to explain multiple interactions. Power is a socially embedded phenomenon and, therefore, the transactions and relationships included in supply networks should also be taken under scrutiny. Thus, the aim of this study is to analyze the impact of network effects and the influence of power on the nature of collaboration between buyers and suppliers within a supply network. The case study analyzes the issue in the Finnish food industry. The results show that the power relations have an influence on the nature of the relationship, and the sources of power that are based on the network effects may crucially determine the power position of the network actor and, moreover, the power relation between two actors.