To ensure universal access to water supply and sanitation (WSS) services that are safe, reliable, sustainable, and affordable, it is important to attract the right types of financing and identify the aspects that could be hindering the success of WSS projects. In this study, 62 completed World Bank WSS projects were analyzed to understand the relationship between project characteristics, bank performance, and quality of results. The methodological approach included a systematic quantitative review and comparative, statistical, and regression analyses, considering important aspects of the projects. The existence of correlations and interactions between project results, bank performance, and key aspects of the projects (such as type of project, initial and final risk assessments, commitments and disbursements, and other characteristics) was observed. This study highlights the importance of rating and mitigating WSS project risks (especially the environmental, social, political, and governance risks) and the importance of development bank financing. The applied methodology could be used by both financiers and borrowers.