The annual increase in cases of oncological diseases dictates the need to search for and develop new methods for diagnosing and treating cancer. The article presents the results of the analysis of modern literature sources devoted to CAR T–cell therapy, which has become a breakthrough trend in the treatment of a number of hematological tumors. The basis of CAR T–cell therapy is the creation of a pool of tumor–specific cytotoxic lymphocytes by introducing an ex vivo transgene encoding a chimeric antigen receptor (CAR). The article outlines the basic principles, possible complications, the advantages and disadvantages of CAR T–cell therapy.