Evaluation of blood cultures depends on clinical fe atures of the patients. Resistance pattern of the strains in every clinic should be known due to empiric treatment of patients which stayed a long time in a hospital, performed therapy with wide spectrum antibiotics and infected with resistant hospital bacteria. Blood cultures obtained from child patients hospitalized at Haseki Education and Research Hospital were evaluated in this study. In 2002, 1019 samples and in 2003, 1062 samples were sent. The blood cultures were examined by the BACTEC 9050 (Becton Dickinson) system. Growth of bacteria were detected in 303 and in 357 blood samples in 2002 and 2003 respectively. We evaluated dispersion of bacteria isolated in 2002 and 2003, their antimicrobial sensivity features and nosocomial outbreaks in pediatrics. Among the isolated strains, 230 of them were Gram-positive coccus and 46 were Gram-negative bacteria in 2002 and 284 were Gram-positive coccus and 48 were Gram-negative bacteria in 2003. Forty one out of 199 and 39 out of 253 coagulase negative Staphyloccus (CNS) were resistant to meticiline in 2002 and 2003 respectively. By using ATB BLSE (Bio Merieux, France) egiht of nine Klebsiella strains were detected as ESBL positive in 2002. Ten of 21 Klebsilla strains were isolated in two months period in 2003. Six Streptoccus pneumonia strains detected in 2002 were moderate sensitive to penicilline G by E. Test. Antibiotic resistance patterns of Klebsiella strains showed that bacteria isolated in 2003 were more sensitive againts all antibiotics tested than 2002.