ABSTRACT Research on regional innovation systems (RIS) suffers from two research gaps: The lack of focus on the entrepreneurial dimension and the dominance of empirical studies on intraregional networks and linkages between innovative actors. Referring to the agenda set by Oinas and Malecki, this paper deals with both interrelated issues. It is shown that while intraregional connections are without any doubt of great relevance for the functioning of RISs they bear the risk of lock-in effects. The complementary importance of extra-regional relationships for the innovativeness of economic regions is emphasised. Entrepreneurial migrants play a crucial role in such relationships. This paper provides a discussion of the five dimensions of proximity recently introduced by Boschma. It is argued that geographical proximity is only one, but often not the most important dimension. For international connections of innovative actors within RIS, cognitive and institutional proximity might be even more relevant.