The conduct and quality of investigations pursued by the Office of the Prosecutor of the International Criminal Court have come under increasing scrutiny and criticism from judges on the Court. Criticism is directed at the time and length of investigations; the quality of the evidence advanced in court; the inappropriate delegation of investigative functions, and the failure to interview witnesses in a way that is consistent with the Prosecution’s obligation to conduct investigations fairly under Article 54 of the Rome Statute. This essay explores these criticisms and concludes that the judges are justified in their concerns regarding the Prosecution’s investigative practices. The Office of the Prosecutor must address these criticisms with a sense of urgency and take remedial measures to ensure that investigations are effective and conducted by qualified personnel according to generally accepted principles of criminal investigation and the rules of the court.