The paper provides guidelines for managers and technical staff in extension agencies who plan, organize, implement and utilize monitoring activities and, when necessary, subsequent evaluations. It defines the information needs of extension managers, discusses administrative and logistic requirements, and reviews techniques for data collection, analysis, presentation and dissemination which experience has shown to be realistic and timely for extension agencies. The Training and Visit approach to agricultural extension services facilitates the organization and utilization of a monitoring system because of its detailed work programs, intensive training and supervision of field agents, and systematic feedback from the farmers to management. The paper focuses on extension agencies using the T & V approach but is of general application for any extension method.