To identify and characterize the isolated bacteria from blood of pediatric cancer patients with fever, blood cultures were done and identifi cation was carried out by conventional methods and API (for Gram negative bacteria), then molecular characterization by Pulsed Field Gel Electrophoresis (PFGE) was done. Th is study was conducted on fi ft y pediatric cancer patients with fever. Th e results of this study indicated that bacterial blood stream infections were detected in only 22% of patients, Gram positive bacteria were more commonly isolated than Gram negative bacteria and Coagulase negative Staphylococci (CONS) were the most commonly isolated species. Th ere was a signifi cant association between the prolonged hospital stay and the presence of neutropenia with the increased incidence of bacterial (Blood Stream Infection) BSI. Th e analysis of PFGE patterns produced showed identical profi les for most of the isolated bacterial strains.