The Guidelines on Municipal Wastewater Management are a practical guide for decision-makers and professionals on how to plan, design, and finance appropriate and environmentally sound municipal wastewater discharge and treatment systems. It contains chapters on (i) an enabling policy environment for sustainable wastewater management, (ii) institutional arrangements and social participation, (iii) planning sustainable and cost-effective technologies, and (iv) financial mechanisms for wastewater management. Four checklists on each of these chapters are practical tools for decision-makers and managers alike. Earlier versions of this guide were based on a report usually referred to as “Recommendations for Decision-making on Municipal Wastewater” and on a background document “Strategy Options for Sewage Management to Protect the Marine Environment” prepared by IHE, IRC and NEI. In 2001 and 2002, version 2.1 of the guidelines formed the basis for extensive review and discussions at regional level with a variety of stakeholders, including national and local experts, representatives of non-governmental organisations, the private sector, professional organisations, and the Regional Seas, Regional Seas offices and Coordination Units. The contents of this document are shared with the Sanitation Connection Database at: www.sanicon.net and is also available at www.gpa.unep.org/documents/sewage-docs.htm