This study assesses for the first time the environmental sustainability of development organizations involved in North–South cooperation by quantifying the carbon footprint as a widely adopted indicator. Our objectives are to (1) analyze the criteria that should be met for correct greenhouse gas accounting of development organizations, (2) gain insight into the emission profile for a limited sample of development organizations from Belgium and Germany, and (3) set forward policy options for more sustainable practices. Carbon footprints are calculated following official guidelines and include available data from different institutions. Mobility of staff is on average responsible for 60% of total annual emissions of the organizations under study, mainly owing to air travel (40%), followed by electricity and heating of offices. These emissions may be partially offset through voluntary carbon market transactions or within development projects themselves. Either approach requires the adoption of high standards of carbon accounting by development organizations. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.