This report summarizes lessons learned from implementing Environmentally Sound Technology (EST) pilot projects by the International Environmental Technology Centre of UNEP Division of Technology, Industry and Economics (UNEP-DTIE-IETC). The document aims to inform national level mainstreaming of the EST pilot project results, and provides lessons learned for decision-makers in national governments and for international technical cooperation personnel. The featured projects were conducted within three pillars of IETC's focal areas. They are: Support for Environmental Management of the Iraqi Marshlands project in the water-sanitation pillarIntegrated Solid Waste Management project in China, India and Lesotho under the waste management pillarand ESTs for Building waste Reduction in Indonesia (DEBRI) project under the disaster management pillar. Each project and cross-cutting lessons learned focus on six areas, which are project management structure, governance, capacity building, EST implementation, financing, and local conditions/infrastructure.