At the institutional core of governance systems based on the rule of law is not only a strong independent judiciary but also an effective prosecution service committed to upholding the rule of law and human rights in the administration of justice. There are many aspects in the responsibility of prosecutors to promote and strengthen the rule of law, including their duty to combat impunity and ensure the lawfulness of State actions. This paper reviews some of the challenges that prosecutors can anticipate in performing their responsibility to uphold the rule of law. It also touches upon some of the issues that have emerged in recent years in relation to the performance of that important function in the context of emergency situations (e.g. counter-terrorist activities), within the global regime of international cooperation in criminal matters and in the context of post-conflict reconstruction and peace-building initiatives.