Purpose: This review paper presents an overview of changes in agricultural extension on a global scale and helps to characterise on-going developments in extension practice. Design/methodology/approach: Through a critique and synthesis of literature the paper focuses on global political changes which have led to widespread changes from production- to market-oriented extension systems and goes on to discuss pressures on unsustainable public extension systems to reform. Findings: It is estimated that there are over 800,000 official extension personnel globally, most of whom work in the public sector in developing countries. This review highlights the important consequences for developing countries of global extension reform and the high percentages of farmers reliant on agriculture, making effective agricultural extension a key strategy in tackling poverty and strengthening rural development. It outlines the manner in which governments around the globe have experimented with alternative approaches to extension reform, such as privatisation and cooperatives, and demonstrates how public sector extension has come to be viewed as problematic. Practical implications: This paper identifies the practical realities of adopting alternative approaches to extension, especially in the context of poverty. It considers the challenges in reforming extension to act as facilitator and enabler, rather than as service provider, and the difficulties in moving towards reforms that promote pluralism and innovation. Originality/value: This paper contributes to current global debates on reforming agricultural extension by providing learning of how extension services have changed. The paper provides new insights from which lessons can be drawn for future extension reform.