The article discusses the implementation of privatization policies in the Kenyan water and sanitation sector in the late 1990s. It addresses the decision taken by the Kenyan Government, with support from the international financial institutions, to introduce reforms aimed at commercializing the provision of water and sanitation services, including the transfer of management and operation activities to private companies. The article provides information about the overall situation of water and sanitation services in the country and presents results from two case studies involving different experiences of private sector participation, in the towns of Nyeri and Tala. It extracts lessons and discusses positive and negative results, implications and prospects of privatization of essential public services in Kenya. The SPIPRW Series has the objective of making available edited materials based on the final reports of the PRINWASS Project(https://waterlat.org/projects-2/prinwass/). This project was carried out between 2001 and 2004 and was funded by the European Union’s Fifth Framework Programme. The project carried out case studies in Argentina, Bolivia, Brazil, England and Wales, Finland, Greece, Kenya, Mexico, and Tanzania, and developed comparative analyses of the main findings. Although the original reports were freely available by request, and we produced several specific publications based on the project’s findings, much of the material remains largely unknown and, for this reason, we launched the SPIPRW Series to facilitate the dissemination of research results.