Pseudomonas aeruginosa is one of the leading antibiotic-resistant gramnegative organisms associated with nosocomial infections. Multiple pathogen resistance leads to the low antibiotic therapy efficiency. This situation requires developing novel antibacterials. The T3SS (type three secretion system) is a key factor in Pseudomonas aeruginosa virulence. This review presents a brief description of the T3SS structure and T3SS regulation, which determines a wide range virulence of gram-negative bacteria with a different types of parasitism and is extremely necessary for the manifestation of the pathogenesis of diseases caused by them. The secreted apparatus forms after bacteria and eukaryotic cell contact and starts the process of transferring the pathogenicity factors directly into the host cell. The regulation activity is a strictly hierarchically structured process that occurs at least at two levels, transcriptional and secretory. T3SS is one of the most attractive target for developing antibacterials as it possesses a number of advantages in comparison with antibiotics: T3SS inhibitors do not contribute to the formation of resistant forms in microorganisms, since they do not suppress the reproduction of pathogens, but only reduce bacterial virulence; inhibitors act regardless of acquired resistance; the therapy with these inhibitors will not cause dysbacteriosis. To date, a number of gram-negative bacteria T3SS inhibitors with various nature and different mechanism of action have been identified. The described inhibitors can suppress the transcription of the T3SS genes, toxins translo cation and act on the effector molecules, according to the mechanisms of action. For many of the developed inhibitors, their specific activity was shown in in vitro experiments. But only in some cases the efficiency of the suppression was shown in animal models. Only three inhibitors are in clinical trials now: the Fluorothiazinone and the antibodies MEDI3902 and KB001.