The purpose of this retrospective study was to evaluate the blood cultures sent to the Central Laboratory of Gaziantep University Hospital between July 2005 and July 2006. In this period 3937 blood cultures were sent to the laboratory. There was no growth in 2821 of these specimens (71.65 %), 25 specimens were (0.63 %) false positive and 57 specimens were (1.44 %) accepted as contamination. Various bacteria were determined in 1034 specimens (26.26 %); 669 of these organisims were (64.70 %) grampositives, 257 were (24.85 %) gram-negatives and 108 were (10.44 %) Candida spp. Of gram-positive bacteria 460 (68.75 %) were coagulase-negative staphylococci (CNS) and 67 (26.07 %) of gram-negative bacteria were Escherichia coli. Methicillin resistance were in 77.39 % of CNS and in 38.46 % of S. aureus. Glucopeptide resistance was not found in Staphylococcus and Enterococcus. Imipenem was found to be the most effective antibiotic on E. coli and Klebsiella spp., and there was no resistance to imipenem. Amikacin and piperacillin-tazobactam were the most effective antibiotics on Pseudomonas aureginosa.