This study examines the role of different networks, called the relational mix, on the development of the entrepreneurial firm. Our regression analysis of survey data from 60 venture capital-financed firms questions the importance of network size on firm development. Rather, our results suggest that different types of networks are more important for firm development. In particular, we found a significant positive relationship for reputational networks and a weak significant negative relationship for cooperative technology networks at founding with time-to-break-even. Social networks at founding have no direct effect on time-to-break-even and a significant negative relationship with sales in the years after foundation. Furthermore, our findings show the important role of marketing information and co-opetition networks (relationships with direct competitors) on firm development in the years after foundation. These results suggest that the relational mix is a more appropriate construct for explaining network development than network size alone