The current study was carried out on 35 children suffering from typhoid fever. They were subjected to blood, stool, and urine cultures as well as Widal test. Inverse PCR was also done for isolated S. typist to evaluate the degree of insertion sequence 200 (IS 200) polymorphism with respect to copy number and location in the bacterial genome. 30 cases (85.7%) were positive by culture for S. lypizi, while 25 cases (71.4%) were positive by Widal test. It was possible to distinguish 14 clonal lines (CL) revealed 4 1S200 fingerprinting patterns (PAT), and the PAT 1 was the most frequent one (46.6%). Conclusion: IS200 fingerprinting allowed the identification of genetically related S. typist It is useful for the identification of outbreak versus of epidemiologically unrelated isolates. The IS200 typing is considered as a tool for revealing molecular epidemiological relatedness among strains of S. typht |