Abstract This article examines the principles of accountability applied by the European Investment Bank in comparison with the practices of other Multilateral Lending Institutions. After a brief description of the EIB and its activities, the substantive and procedural principles governing the EIB's external accountability are reviewed. The substantive accountability principles considered are the applicable rules of the EU legal order and the voluntary human rights, social and environmental principles and standards which the EIB has identified for itself and committed to follow throughout its operations. The article evaluates the extent to which these norms form a credible normative framework against which the EIB's lending practices can be appraised. From a procedural accountability point of view, the article assesses the transparency and participation policies of the EIB, as well as the mechanisms offered to external stakeholders to seek redress from the EIB in case they are wronged by one of its decisions. The redress mechanisms analysed are the recent EIB's Complaints Office, the European Ombudsman and the Court of Justice. We conclude that the EIB should take more advantage of its being subjected to the EU human rights, social and environmental rules and of the EU judicial apparatus in order to upgrade its substantive and procedural accountability towards external stakeholders.