Dual and/ multiple citizenship (bipatrism and polypatrism), which creates a large number of problems for states in various fields, makes it necessary to study traditional and modern trends in the legal regulation of these complex social phenomena. The objectives of the paper are determined by the need to identify the main directions of international and domestic practice regarding the content, legal features of regulation, as well as the political and legal consequences of bi- and polypatrism. In the course of the analysis, attempts are made to compare, generalize the similarities and differences between the elements of the concepts of «dual» and «multiple» citizenship, as well as their differentiation. The paper discusses domestic and international legal regulation cases in the field of dual and multiple citizenship, as well as the practice of states in resolving the problems generated by these phenomena. The author makes a conclusion about the difficulties of an objective order in relation to the development of uniform approaches to measures to regulate dual and multiple citizenship on a wide international scale. This happens due to the presence in the law of various states of individual features of an ethnohistorical, sociocultural, religious and other nature that affect the current state of legal reality in this matter. Besides, there is a complex interweaving of negative and positive elements that make them up, and the corresponding general and particular consequences.