Effective irrigation service provides the environment for productive and sustainable agriculture vital for incomes and employment, economic growth and lifting people out of, and keeping them out of, poverty. Poorly managed irrigation can have the opposite effect. Irrigation performance assessment is an important management tool to aid in providing sound service. Performance assessment in irrigation and drainage is the systematic observation, documentation and interpretation of activities related to irrigated agriculture with the objective of continuous improvement. In this paper we provide basic concepts of performance assessment, then pay particular attention to aspects of performance assessment and service provision related to poverty alleviation. Particularly important are the management specifications for irrigation service, providing rules for access to water and payment for service. Inequitable access to water and poverty in irrigation are related to the degree to which specifications are met; who is included and excluded from the specifications; and whether specifications encompass the multiple uses and users of water. Primary focus for irrigation service has typically been given to irrigated crop farmers. For poverty alleviation, service provision and related performance assessment programmes need to give due attention to the many other people dependent on irrigation water including the landless, livestock keepers, fishermen and domestic water users. Advances in performance assessment techniques are needed in this area. Copyright lutter contre la pauvreté, la fourniture du service et les programmes d'évaluation des performances doivent prêter une plus grande attention aux nombreuses autres personnes qui dépendent de l'irrigation, tels que paysans sans terre, pasteurs, pêcheurs, et usagers d'eau domestiques. Les techniques d'évaluation des performances doivent faire des progrès dans ce secteur.