This chapter focuses on the question of how United Nations High Commissioner for Refugees (UNHCRs) adoption of new biometric registration technologies in an ever-increasing range of refugee contexts may affect upward and downward accountability in the context of UNHCRs refugee protection activities. It provides the issue of challenges to UNHCRs expectations regarding the ability of biometrics to act as an accountability-improving technology. Although measures have been taken to address a number of accountability challenges, an important point to stress in the chapter is how the use of biometrics may give rise to new accountability challenges, notably concerning the use and storage of biometric refugee data. Such data protection challenges have, indeed, been stressed by a number of international privacy experts, who have for example said the following about UNHCRs use of refugee biometrics. The current focus on humanitarian accountability, combined with the securitization of humanitarian practices, is creating pressures for the humanitarian world to take on new methods and tools.