Small and medium-sized enterprises (SMEs) face critical challenges in implementing collaborative strategies, including the difficulty of finding partners, the strain on managerial resources, and the risk of exploitation by larger partner firms. However, little is known about tendencies to network in SMEs. This paper builds on organizational economics and the resource-based perspectives. Survey data from 348 German SMEs reveal that predictions from both theories play a role for the tendencies of SMEs to network, yet organizational capabilities in terms of coordination and communication and bonding in alliances are most relevant for cooperation decisions. We provide managerial implications for cooperation involving SMEs. Copyright © 2012 John Wiley & Sons, Ltd.