The main aim of this article is to present the denaturalization institution in different modern legal systems. Loss of citizenship should be considered in the context of right to citizenship. According to many sources right to citizenship should be counted among the human rights. Unfortunately, there is still no consensus between governments on this issue. However, it is worth mentioning that national authorities are limited in establishing nationality law, which arises mostly form international rules of law. The first part of article is dedicated to the presentation of the idea of right to citizenship. It focuses mostly on current reflection of this right in international and domestic regulations. The following chapters describe acceptability and use of denaturalization. Because of high diversity of national laws, the author presented the most unusual ones.