Our introduction provides the foundation and background for this special issue on open innovation. Since the beginning of the 21st century, innovation has evolved from being the artefact of an individual or internal process within firms to an interactive process between firms and/or in collaboration with knowledge-creating institutions at both the domestic and global levels. The open innovation model suggests that firms should combine external and internal ideas and technologies as effective pathways to market when advancing and commercialising technologies. However, existing research focuses mainly on high-technology multi-national firms hence, theoretically driven and empirically-based research exploring open innovation in small and medium-sized enterprises remains relatively scarce. This special issue offers a critical contribution to this gap with four articles which explore differing aspects of open innovation within smaller firms. The introduction to this special issue commences with an overview of the relevant literature; it then describes the articles and, finally, suggests potential avenues for future research.