The bar as an institution of civil society ensures the protection of the rights and freedoms of citizens, guarantees fair justice. A lawyer has long been called a defender – who protects a person, his or her rights and legitimate interests. In the legal system of the Republic of Kazakhstan, attorney-client privilege is considered as a moral and ethical problem at the level of self-governing structures of the bar. The lack of sufficient scientific and theoretical research on the problems of attorney-client privilege, the uncertainty of the status of the bar both in the system of the Institute of defense and justice itself lead to the unsettled legal status of attorney-client privilege, which also determines the relevance of the topic of scientific research. The purpose of the study is a historical and legal analysis of the content of "attorney-client privilege"; identification of gaps in the legal regulation of the concept, content and guarantees of attorney-client privilege, taking into account the provisions of the Constitution of the Republic of Kazakhstan and international legal acts in the field of human rights; identification of ways to solve problematic issues of ensuring attorney-client privilege. The methodological basis is a set of general scientific and philosophical methods that made it possible to disclose the subject of research and achieve the goal. The article substantiates a number of theses: attorney-client secrecy is considered on the basis of quantitative and qualitative methods of law analysis and a broad base of moral, ethical, historical and legal problems of protecting human and civil rights and freedoms; attorney-client secrecy and the problems of advocacy are considered in the system of social and, in particular, legal institutions as a process of institutionalization in general. In other words, the need for objective knowledge of public relations is actualized, the main element of which is legal relations, and a specific area is secrecy; the system of legal relations that arise in connection with the need to observe attorney-client confidentiality, the system of legal support of attorney-client confidentiality for the successful implementation of their activities by lawyers and to increase confidence in the lawyer in the state is analyzed.