The genus Raoultella belongs to the family of Enterobacteriaceae. Raoultella spp. are Gram-negative, aerobic, non-motile rods. This genus can be distinguished from the genus Klebsiella, in that genus use histamine as the only source of carbon in the medium. Also, Raoultella grow at 4 °C and do not produce gas from lactose at 44.5 °C. Raoultella sp. is known to inhabit natural environments (water, soil, plants). The reservoir of Raoultella is the gastrointestinal tract and upper respiratory tract. Raoultella spp. are opportunistic bacteria, which usually cause infections of the biliary tract, pneumonia and bacteraemia in oncologic and with lower immunity patients. Raoultella planticola and Raoultella ornithinolytica are the most frequently encountered human pathogens among the genus Raoultella. Matrix-assisted laser desorption/ionization–time of flight (MALDI-TOF) mass spectrometry has been used for identification of bacterial isolates, has demonstrated overall good performance in the identification of gram-negative bacilli, and can correctly identify and differentiate Klebsiella from Raoultella spp.