Gram-negative bacteria Stenotrophomonas maltophilia rank third among non-fermenting gram-negative bacteria in terms of detection frequency in various infectious pathologies. This review presents information on the various virulence factors, mechanisms used by S. maltophilia for colonization and infection of the human body, multiple drug resistance, clinical manifestations of the diseases caused, and methods of bacteriological diagnosis. The importance of early identification of this pathogen for practicing physicians is emphasized. The selection of treatment for infections caused by S. maltophilia is discussed, highlighting the challenges faced by both clinicians and microbiologists. To this end, current domestic and international scientific publications were reviewed using scientific electronic library search engines such as PubMed, Google Scholar, eLIBRARY.ru, and CyberLeninka.