The operational programme for Sustainability and Use of Resources (POSEUR 2014-2020) is the most powerful mechanism of EU Cohesion Policy to be implemented in Portugal concerning sustainable environmental development. The programme has a place-based approach that attends to the territorial characteristics of the Portuguese regions. This study focused its analysis on the POSEURS’ main impacts on the Portuguese Centre NUT II. With a mixed methodological approach, impact scores were produced for five environmental sustainability dimensions: i) low-emissions economy, ii) adaptation to climate change, iii) risk prevention and management, iv) environmental protection, and v) resource efficiency. The qualitative and quantitative data was collected through interviews, literature review, the POSEUR project database analysis and regional environmental indicators. The outcome of the analysis showed that technical and execution barriers contributed to the heterogeneity of the results obtained in the five selected dimensions. An overall balance points out the low positive impact scores promoting small regional changes in environmental sustainability. Nonetheless, elaborating spatial plans for the municipalities and regions turned the adaptation to climate change into a highly positive impact dimension.