The article deals with the question of right to healthcare as it is set by the Charter of Fundamental Rights and Freedoms of the Czech Republic and at the same time with the question of rationing in healthcare. Rationing in healthcare generally means a process realized by providing different levels of healthcare. In the Czech Republic, rationing in healthcare is rather based on a limitation of a treatment’s payment from public health insurance which, however, does not fit the common definitions of rationing. By describing and explaining these crucial questions the article discusses the possibility to limit the constitutional right to healthcare covered by public health insurance in the Czech Republic and shows these possibilities which are based on provisions of the Act No. 48/1997 Sb., on public health insurance. More widely it questions whether the system of public health insurance in the Czech Republic is sustainable at all.Keywords: Healthcare. Rationing. Public health insurance.