This 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. fyplii to evaluate the degree of insertion sequence 200(1S 200) polymorphism with respect to copy number and location in the bacterial gcnomc. 30 cases (85.7%) were positive by culture for S. typlii, wliilc 25 cases (71.4%) were positive by Wicial lest. 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: 1S200 fingerprinting allowed the identification of genetically related S. fyplii. It is useful for the identification of outbreak versus of epideniiologically unrelated isolates. The 1S200 typing is considered as a tool for revealing molecular epidcmiological relatedness among strains of S. typlii