We are glad to present another issue of the PRINWASS Project Series (SPIPRW). 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. This issue of the WATERLAT-GOBACIT Working Papers features two articles presenting edited materials based on the original reports from the case studies carried out in Kenya and Tanzania. These two cases provide examples that have important lessons for current debates on the privatization of essential public services in developing countries, as we currently experience a revival of the water politics implemented worldwide in the 1990s, often with complete disregard for the lessons learned from the recent past. The two Kenyan cases examined in Article 1 provide excellent information about the overall situation of essential water services in the country, and a detailed account of the process of privatization launched by the government in the mid-1990s with the support of international financial institutions and development agencies. In practice, the two cases under consideration in the article, the experiences of Nyeri Town and Tala Town, are mostly cases of commercialization of water supply services. Article 2 discusses the implementation of privatization policies in Tanzania, which took place around the same time than in Kenya, and under relatively similar circumstances, with a strong presence of international financial institutions and development agencies providing support and funding for the required reforms. The article focuses on the privatization of the capital city Dar es Salaam's public utility, DAWASA, which was a very difficult experience and took almost six years to be completed. Differently from the Kenyan cases, where the participating private companies were local, in Dar es Salaam there was a strong presence of multinational water companies. The original reports were written in 2003 and 2004, and therefore the articles contain references that may be outdated. We have not updated the information, as the purpose of the publication is to disseminate the original information. We hope that the readers will find this material useful and that it may contribute to the work of researchers, students, activists, and others in their activities to understand better the internal workings and the huge impacts of water privatisation processes. As mentioned earlier, these policies are not only very much alive but are also experiencing a worldwide revival. Therefore, we believe that the findings and lessons that emerged from the PRINWASS Project deserve this publication effort.