The regeneration of urban brownfields is a relevant strategy to limit the sprawling of post-industrial European cities. However, the integration of sustainability issues in urban brownfield regeneration projects is not a spontaneous process, remaining in most cases partial or superficial. Achieving the goals of sustainable development requires high global quality objectives, integrated into the project dynamics, and a continuous monitoring of environmental, social, and economic indicators, adapted to the specificities of brownfields. Following these considerations, an operational monitoring tool facilitating the transformation of urban brownfields into sustainable neighborhoods was created. This paper presents and discusses the verification stage of the tool, divided into two complementary tests: 1) test-applications on three case studies in Belgium, France and Switzerland and 2) interactions with the involved stakeholders. First, we describe the functioning of the tool. Then, we present the test-applications results, supported by the Val Benoit project in Liège (Belgium) as an example. They are followed by the interactions with the stakeholders that took the form of roundtable discussions. Finally, we discuss the performance of the tool looking at its potential added value. It reveals that an adapted operational monitoring tool can facilitate sustainability assessment, reporting, decision-making and multidisciplinary collaboration. Globally speaking, the integration of monitoring practices appears not only feasible, but also realistic and desired.