Ports are core nodes for multimodal transport in the Adriatic-Ionian basin and strategic key drivers for economic growth: reducing negative environmental impacts is essential for a sustainable development of the area. SUPAIR responds to a major challenge (EUSAIR strategy, pillar 2, topic 1), in that it tackles reduction of emissions from shipping and on-shore port operations with an integrated approach, enhancing port authorities’ capacity to plan and implement low-carbon and multimodal transport and mobility solutions and further empowering the main political, technical, trade stakeholders and partners in related decision-making. SUPAIR firstly establishes a TRANSNATIONAL NETWORK of port authorities, technical organizations, relevant actors to jointly elaborate the project’s durable and transferable methodology; then develops operational ACTION PLANS complete with technical and feasibility studies in the 7 partner ports; ultimately implements dedicated actions and produces a TRANSNATIONAL STRATEGY for port-based low-carbon transport systems to increase the network, disseminate, enhance and widen scope, methodology and results. The transnational development and implementation (3 EU and 2 IPA countries) of methodology and actions insisting on a broad range of fields, with an innovative territory-based approach, involving port authorities, technical partners, stakeholders and institutional actors guarantee quality, durability and transferability. SUPAIR’s impacts are short-term (7 operational plans developed) and mid- to long-term plans implemented and financed, new actions undertaken following the established methodology by an enhanced and widened network of ports. Benefits for the involved territories embrace enhanced technical capacity for ports, increased empowerment of relevant local organizations and institutions, improved environmental quality and attractiveness, increased investments in low-carbon and environment-friendly port transport and mobility solutions.