Bacteria utilize a wide range of regulatory systems to adapt to life in various environmental conditions. Among these regulators small non-coding RNAs (ncRNAs) play a particularly important role. Acting primarily at the post-transcriptional level, small ncRNAs enable bacteria to rapidly adjust gene expression in response to external influences. They are involved in the regulation of almost all cellular processes, including replication, transcription, translation, energy and general metabolism, antibiotic resistance, bacterial virulence, as well as mechanisms associated with bacterial pathogenesis. Bacterial small ncRNAs are capable of mediating interactions between the bacterium and the host organism, directly modulating the expression of eukaryotic genes (most often those related to the immune response). Thus, ncRNAs serve as universal and powerful regulatory elements that ensure the survival and active functioning of bacteria under any adverse conditions.