Objective: The aim: To determine the grounds of involuntary admission of a mentally ill person in the context of the possibility to restrict his or her right to liberty.
Patients and methods: Materials and methods: The authors have studied and analyzed international legal acts, legislation of certain countries, judgments of the European Court of Human Rights, case law on involuntary admission of a mentally ill person by using philosophical, general and special scientific research methods.
Conclusion: Conclusions: The imperfection of the legal regulation of relations concerning the involuntary admission of a mentally ill person leads to illegal restriction of the personal right to liberty. It has been proven that involuntary admission and restriction of the freedom of a mentally ill person can be justified, if we take into account the requirement of "therapeutic necessity" for a mentally ill person, the requirement of protecting the rights of others and guaranteeing their safety, the requirement of ensuring the best interests of a mentally ill person.
Keywords: a mentally ill person; human rights; involuntary admission; restriction of the right; the right to liberty.