Etiologic diagnostics of sepsis is one of the most difficult problems of contemporary medicine due to a wide variety of sepsis causative agents, many of which are components of normal human microflora. Disadvantages of contemporary "golden standard" of microbiologic diagnostics of sepsis etiology by seeding of blood for sterility are duration of cultivation, limitation in detection of non-cultivable forms of microorganisms, significant effect of preliminary empiric antibiotics therapy on results of the analysis. Methods of molecular diagnostics that are being actively developed and integrated during the last decade are deprived of these disadvantages. Main contemporary methods of molecular-biological diagnostics are examined in the review, actualdata on their diagnostic characteristic are provided. Special attention is given to methods of PCR-diagnostics, including novel Russian developments. Methods of nucleic acid hybridization and proteomic analysis are examined in comparative aspect. Evaluation of application and perspectives of development of methods of molecular diagnostics of sepsis is given.