With sustainability-oriented innovations (SOIs) small- and medium-sized enterprises (SMEs) can conquer niche markets, cut resource usage and improve the quality of life. SMEs follow different strategic orientations for SOIs. They are conditioned by their organizational structures, capabilities and interaction with the business, regulatory and knowledge network. Usually, SMEs find it easier to span their boundaries to the business network. This research explores, in a longitudinal multi-case study, how the interaction with the knowledge network can condition an SME's strategic orientation. In the analysis of a learning-action network established by a research institute, three network-patterns (grazer, explorer and networker) are observed which result from different SME boundary-spanning processes. A central role is played by the boundary spanners who influence to which degree the SME can build up exploratory and exploitative learning capabilities to further deploy, push forward or generically develop its strategic orientation for SOIs in interaction with the knowledge network.