This article explores the phenomenon of judicial dissents at the ICC. The main subject is the process of collective decision-making and judicial deliberations in cases where members of a particular ICC chamber cannot reach a consensus on factual, substantive or procedural issues and render a unanimous decision. The article examines why and when international criminal judges dissent according to the views expressed by ICC judges. Drawing heavily on field research in The Hague, the article presents a qualitative analysis of the ICC judges’ perceptions and experiences of using dissenting opinions at the Court. Empirical findings derived from interviewing ICC judges support the hypothesis that international criminal judges’ personality, that is, their character differences (such as self-discipline and other work habits), their previous career experience, and their field of expertise determine their likelihood of using judicial dissents. In case of disagreement within an ICC Chamber, judges with criminal law backgrounds who previously worked as professional judges are more likely to append their dissent to a majority ruling with which they do not agree than international judges, diplomats, and professors with public international law expertise who are more willing to discuss and negotiate in order for the Court to speak with one voice.