Abstract: In its last revision EMAS Regulation has encouraged a cluster approach to increase the participation of the organizations and to involve local stakeholders in a cluster sustainability process. Our research activity, conducted by the Department of Business Studies of Roma Tre University and ISPRA (High Institute for Environmental Protection and Research), intends to partially fill the literature gap in the field by investigating the Italian cluster approach for EMAS, characterized by the creation of a cluster Managing Committee (MC) – which has received a dedicated EMAS certificate – that coordinates the implementation of the scheme. If in a first phase we investigated the effectiveness of support given to registered EMAS organizations inside the cluster by the MCs that possess an EMAS certificate, the main objective of the second step here presented has been to verify the impact on different stakeholders categories of the actions taken by the various MCs in 12 Italian clusters. In this paper we present the results of a survey conducted through the distribution of a specifically designed questionnaire on different categories of stakeholders in the considered clusters. These three categories are the 67 organizations certified ISO 14001 in the cluster’s areas, the 100 municipalities of the areas and the 9 chamber of commerce involved in the Managing Committee of the clusters. The main two goals of the investigation are: to determine the impacts of the action put in place by the Managing Committee inside the clusters, in terms of environmental performance enhancements and network creations to improve the cluster competitiveness; to evaluate how the tools offered to cluster organizations have effectively contributed to a widespread knowledge of EMAS and environmental concerns.