The rapid urban development, the Agenda 2030, the climate change adaptation and the COVID 19 crisis high light the need to increase investment in public infrastructure and improve water supply and sanitation services. For this, an alternative to traditional public procurement is the participation of the private sector under the public-private partnership (PPP) model. The objective of this article is to develop a tool based on critical success factors (CSFs) that allows for evaluation during early stages of the convenience of developing a PPP project for W&S in urban areas of Latin America and the Caribbean. The index was developed based on literature review (779 variables), review of cases (20 variables) and expert opinion to assign them an estimated value of importance. The results were analysed by exploratory and confirmatory factor analysis, selecting 17 main variables grouped into 6 CSFs, the most relevant of which are Convenience, Certainty, Leadership, Attraction, Performance and Reliability. The application of this index allows an early assessment of the feasibility of a PPP project and/or the selection of the alternatives with the best chances of success. On the other hand, this study contributes to the international discussion on the most relevant elements related to the success of PPP in W&S projects.
