Irrigation Scheme Operation and Maintenance is the tenth in the series of training manuals on irrigation prepared jointly with ILRI (International Institute for Land Reclamation and Improvement). The manual presents some of the difficulties that irrigation organizations confront in undertaking their duties and provides some orientations on how to resolve them. The paper then proceeds to discuss the methods of operating an irrigation network and the working principles involved. The maintenance tasks are discussed. To draw similarities and differences the maintenance of a motorcycle is used as a reference for the corresponding activities in an irrigation scheme. Finally, a reference is made to the need for having an effective financial control whereby the management of the system has enough resources to undertake the operation and maintenance tasks. The manual is addressed to small and medium schemes and assumes that the management organization is already in place.