The concept of a “right to the truth” gives the families of victims of serious human rights violations an independent enforceable right to learn the truth about what happened to their relatives. The right is rooted in those provisions of international human rights conventions that prohibit inhuman treatment and guarantee effective access to justice. This article traces the evolution of this concept, considers whether it has a correlation in international criminal law and considers some of the synergies that are created as the concept of the right to know continues to evolve as a principle of international law.