In the 1980s, public bodies became aware of the importance of small- and medium-sized enterprises (SMEs) in regional economic development. In order to stimulate their innovativeness and to overcome their inward limits, public policies set up innovation agencies all over European countries. Criticisms arose after 10 years of existence because of their low usefulness. This article aims to develop a better understanding of the relationship between SMEs and innovation agencies. It presents the implementation of a management scheme which experimented with new solutions in French SMEs, to overcome previous gaps. Our article seeks to enrich research exploring the links between the SME and the innovation agencies within knowledge-based clusters. It advocates new principles to improve SMEs' guidance in innovation processes and shows that they are still essential organizations to support SMEs' innovativeness, especially the structurally weak and inward-looking looking ones.