Despite the widespread popularity of the regional innovation system (RIS) concept, its details remain relatively underspecified, while most studies focus on the attributes of a handful of 'ideal type regions'. This makes it difficult to explore how economically weak regions are succeeding in developing their potentially missing RIS elements. By investigating a peripheral region in Greece, this paper argues for deeper interaction among innovation actors and develops a five-dimension conceptual framework useful in analysing bottlenecks to regional innovation.