A forensic expert, as a participant in legal proceedings, carries out important activities to assist in proving the persons conducting the proceedings, as well as to persons who have a legal interest in the outcome of the case. In order to carry out his functions, he is entrusted with a number of duties, the proper fulfillment of which, in the opinion of the legislator, contributes to the high-quality, complete and objective conduct of an expert study and giving an opinion. The expert’s responsibility is established by various codified normative legal acts of the member countries of the Eurasian Economic Union. Several types of liability are envisaged depending on the severity of the consequences of failure or improper performance by an expert of his duties: criminal, administrative, procedural. Nevertheless, the normative consolidation of the expert’s responsibility today does not allow us to speak about the logic and the validity of the established types of responsibility. Analyzing the specified types of expert’s liability, it can be concluded that in some cases the use of certain negative consequences in relation to the expert is disproportionate, there is a lack of a unified approach in different types of legal proceedings to determining the type of expert’s liability.