Despite significant progress, gender inequalities persist in all countries. These inequalities both negate fundamental human rights and present serious barriers to the achievement of national development objectives. Notwithstanding widespread commitment to gender equality by governments and development agencies, and despite the compelling evidence on persistent gender inequalities, conventional M&E systems fail to address gender differences. This note discusses the limitations of M&E systems in understanding gender inequalities and presents guidelines for developing a gender-responsive M&E system (GMES). It draws on international experience of governments, donor agencies, and NGOs to outline the main steps in the design and implementation of such a GMES. The approach will vary depending on whether the GMES is part of a national gender policy or is intended to improve the efficiency and effectiveness of M&E systems at the agency or program level.