Abstract: The UN Human Rights Committee’s General Comment No. 35 summarizes the treaty body’s interpretation of the right to liberty of person, including protection against arbitrary detention, under the International Covenant on Civil and Political Rights, one of the principal human rights treaties at the global level. This essay provides an overview of General Comment No. 35, and then focuses on three aspects that provoked controversy either within the Committee or outside it: the time limit for “prompt” presentation of pre-trial detainees to a judge; the standards governing security detention in non-international armed conflict; and the disagreement between the Human Rights Committee and the Committee on the Rights of Persons with Disabilities regarding whether involuntary hospitalization is ever permitted. These examples illustrate significant issues about the interaction between the Covenant and other international regimes.