The International Water Association (IWA) adopted the Lisbon Charter in January 2015 for guiding the public policy and regulation of drinking water supply, sanitation, and wastewater management services around the world. From the analysis carried out in this article, it can be seen that the public policy instituted in 1993 in Portugal for the water services was according to the principles of the Lisbon Charter in general. It brought together institutional, governance, management, planning, technical, economic, legal and environmental, public health, social, and ethical instruments to ensure the suitable provision of these services. But if the public policy developed in Portugal gave a significant contribution to the preparation of the Lisbon Charter, in the inverse way this modern Lisbon Charter is now giving good support for the consolidation of the national public policy.