With the decline of the mass production system, which had a predominant focus on big companies, there was a readjustment of the productive forces with tendencies to a structure that started to favor the small and medium companies (SMCs), mainly when they act in an united way in industrial clusters and not separately. Starting from the nineties, several studies were developed pointing the calls clusters as a possibility for the competitive insertion of SMCs in the modern economy. Some researchers consider that SMCs, when inserted in clusters can develop a learning dynamic that leads to the process of acquisition of knowledge. The learning by interacting, in particular, is presented as the main responsible for the generation of innovations in SMCs. In that way, this dissertation presents a case study, focusing on the innovations generated by learning by interacting in the marble and granite cluster of Cachoeiro de Itapemirim, which stands out as the main producer of Brazil and as one of the larger exporters of the world. In this cluster two main learning by interacting sources were found: GMC (Group of Continuous Improvement) and Empreender. GMC, in especial, was the focus of this work, which sought to understand, mainly, how the generation of innovations occur through the interaction of the participant companies of that group and among these and the entities of the local governance, as well as to investigate some relevant events of innovation from the point of view of the companies.