This technical note analyzes international experiences and practices of public technology extension service programs. Technology extension services comprise varied forms of assistance provided directly to enterprises to foster technologi cal modernization and improvement, with a focus on established small and mid-sized enterprises. The note discusses the definitions, rationales, and characteristics of selected technology extension service programs, drawing on examples from Europe, North America, and other regions. It presents four detailed case studies : the U.S. Manufacturing Extension Partnership; the National Research Council - Industrial Research Assistance Program in Canada; England’s Manufacturing Advisory Service; and Tecnalia, an applied technology organization in Spain. The case studies address several program elements including the history and evolution of the program, structure, program scale, financing structure, services and clients, governance, personnel, monitoring, and evaluation. The analysis highlights common and distinctive characteristics as well as program strengths, weaknesses, and key practices. The note provides a framework for positioning technology extension services within the broader mix of policies for technology transfer, business upgrading, and innovation , and offers conclusions and insights to support efforts to strengthen technology extension services in Latin America.