With growing public and private support of networks of small and medium-sized firms, many networks rely on network boards to ensure effective governance. By integrating agency and embeddedness reasoning, this article argues that network board composition aimed at effective monitoring may be at the cost of lost ability to strategize. In this study, longitudinal data of Swedish government-supported innovation networks demonstrate that network innovation improves as network board size increases, but that returns to such increases diminish when boards become overly large. Similarly, network board independence is beneficial up to a certain threshold, after which further increases in independence become detrimental. The study clarifies how agency and embeddedness theory can be combined to explain boards’ abilities to combine monitoring and strategizing at the network level in increasing the levels of network innovation.