A Sustainable Urban Mobility Plan (SUMP) is a strategic (long period) transportation plan aimed to improve welfare of both people and workers living in the city as well as in its surrounding area. Compared to “traditional” urban transportation plans, SUMP moves the focus from traffic (vehicles) to people with significant advancements in the direction of a sustainable mobility jointly with the quality of life. According to the recent European Guidelines, this type of strategic plan has to be built on existing planning practices and take due consideration: the integration, the participation, and evaluation. Starting from these considerations, in absence of a detailed national guideline implementing SUMP, the aim of this paper was to apply an innovative theoretical decision-making approachfor the development of the Naples (Italy) SUMP. This case study appears to be interesting because of the specificity of Naples, that is the third largest Italian city and metropolitan area with the highest population density. In 2016, the city of Naples has efficiently concluded and ratified a first formalization of acts: 'The analysis of mobility system' and ‘The statement of strategic objectives