This paper presents an unspoken aspect of Head of State immunity, namely that such immunity is at odds with the expectation that international law should be applied to challenge resistance to and promote respect for human rights. It considers the question of whether Head of State immunity gives rise to de facto impunity in the case of violations of human rights recognised as peremptory norms (jus cogens) committed by such Heads of State. While this paper emphasises the critical role of Head of State immunity in the context of international relations, it argues that Heads of State should not exempt from punishment when violations of those human rights are at stake.