This paper examines a participatory procedure of self-assessment of irrigation system performance by farmers in the Philippines. The procedure was aimed at improving system performance through strengthening irrigators associations' (IA) managerial capacity in planning and decision making regarding operation and maintenance, communication and conflict resolution. The assessment was part of a longer intervention to organize farmers in small groups based on water and task distribution. The first phase involved self-assessment by the original groups of the process of organizing smaller groups and catalysing collective action. In one-day workshops, farmers used symbols and maps to assess the situation. The second phase used a self-assessment questionnaire filled out monthly by IA group leaders, to assess their own performance in a range of management tasks. The experiment showed that participatory self-assessment was quite successful in eliciting candid appraisals of the existing situation. Pictorial analysis was a learning experience in which farmers identified unexpected causes of problems. These problems lay within the farmers' ability to resolve them, so the assessment facilitated follow-up actions to address them, which are listed in a table.