The Gender Performance Indicator for Irrigation (GPII), was developed by the International Water Management Institute (IWMI) and was tested in 9 case studies across the world. This generic analytical tool answers the question whether irrigation institutions in a particular irrigation scheme are gender-inclusive and if not, what can be done to affect change. This report presents the underlying concepts of the GPII and the methodological guidelines for its application. In addition, salient findings of selected applications of the GPII in Asia and Africa are presented to highlight how the tool captures policy relevant variation. The GPII seeks to answer two questions; the first, whether farm decision makers in a scheme are predominantly male, female or mixed, and the second, whether female farm decision makers are included, excluded or a minority in the male farming system.