The organisational and spatial embeddedness of innovator firms is often taken for granted. This paper develops a theoretical synthesis of regional science (milieu innovateur, systems of innovation) and organisation science (resource and activity-based perspective) accounting for the proximity effect (benefiting from localised ties). The resulting research models enable us to derive several hypotheses on factors influencing the organisational and spatial embeddedness of innovation networks. Results of OLS and logistic regression analyses, using an unique firm-level database of 689 manufacturing firms located in the Dutch region of Noord-Brabant, support most of the hypotheses. First, high levels of complexity of innovative activities induce ...