The relevance of business model innovation (BMI) for strategic renewal and competitive advantage has been increasingly recognized by both strategy scholars and managers. In this paper, we explore how inter-organizational networks and firms' proactiveness influence BMI. By examining Dutch design companies, we show that having a network of companies with different sizes has a positive effect on BMI. We also observe a positive effect of ties change. Finally, we show the importance of firms' proactiveness. Through the discussion of network elements and proactiveness as antecedents of BMI, we contribute to the business model and social network literature.