A number of incidents have of late brought attention on the problem of the standards to be followed by the prosecutors of international criminal tribunals. Ethical standards of the profession and ways to make prosecutors accountable seem essential to safeguard the legitimacy of international criminal justice. Domestically, prosecutors' work is often quite strictly bound within certain limits, but internationally it has taken longer for appropriate standards to emerge, and arguably even longer for them to be implemented. This working paper looks at how deontological norms apply to international prosecutors and what it means to describe them as "accountable". Accountability can be defined by reference to narrow professional standards, or broad political objectives, the two being potentially it tension. The paper charts the emergence of the issue as a significant one in the evolution of international criminal tribunals. The need for accountability of prosecutors is then justified from a normative point of view. It distinguishes between different "regulatory models" of accountability, and highlights the sources of ethical standards, to whom exactly they apply and how. Attention is drawn to a number of principles that are presented as particularly relevant such as independence and impartiality; fairness, integrity, propriety, and good faith; professionalism and competence; diligence and expeditiousness; and transparency. The challenge is to make prosecutors accountable in a way that is commensurate with the degree of their fault, and not risk unduly encroaching on their independence. This is achieved by making sure that the responsibilities for enforcing accountability are properly allocated, and by developing mechanisms that are adequate to the task. These can include requiring prosecutors to report on their work, or submitting it to a degree of judicial supervision leading, for example, to the award of remedies to those (typically the accused) who have suffered from prosecutorial wrongdoing. In exceptional circumstances, disciplinary proceedings up to removal may be the only option to guarantee the integrity of international criminal justice, possibly leading to reparations to victims of prosecutorial abuses.