Strategic innovation networks, formed to stimulate innovation performance and eco- nomic growth for members and regions via collaborative activities, have recently be- come increasingly common. Numerous researchers have noted the effect of network structure on innovation performance and also discussed the mediating role of commit- ment. Many studies suggest that commitment strongly mediates firm and network out- come and performance. Studies of organisational behaviour, relationship marketing, and human resources demonstrate that commitment leads to better firm performance, inter- firm cooperation, network performance, market knowledge transfer, knowledge sharing, future intentions, retention, and enforcement mechanisms. Strangely, studies of the re- lationship between commitment and innovation from a network perspective are lacking. This study investigates the relationships between commitment, its antecedents, and in- novation performance in strategic innovation networks. The antecedents examined are expectation gap, shared values, ego network density, and ego network size. A ques- tionnaire was emailed to all members of three Swedish strategic innovation networks in different industries and regions to collect data; 150 completed questionnaires were re- ceived for a 27% response rate. Multiple regression, path, and mediation analyses demonstrate that commitment is an important mediating variable when firms in strategic networks jointly develop innovations. Expectation gap and shared values are strongly related to commitment, but ego network density and ego network size are not; however, the last two variables directly affect innovation. This means that relational influence is more important for commitment than the structural effects, while structural effects are more significant for innovation.