In hospitals intensive care units (ICU) are the departments where resistant bacteria are most prevalent.The purpose of this retrospective study was to evaluate the results of cultures and antibiotic sensitivity tests who had been hospitalized in the ICU of Gaziantep University Hospital between 2000 and 2001. Patients who had stayed at the ICU for at least 72 hours were included only. Totally 171 isolates from various specimens including tracheal aspirate, urine, blood, wound, catheter were included. Most frequently isolated pathogens during this period were Pseudomonas aeruginosa (34.5%), Staphyloccus aureus (SA) (31.5%), and Acinetobacter baumannii (22.2%). Methicillin-resistance (MR) was detected in 82% of S. aureus strains. Vancomycin (100%) was the most effective antibiotic followed by trimethoprimsulphametoxazole (90%) on MRSA strains. Pseudomonas isolates were mostly sensitive to sulbactam-cefoperazone (81%) followed by levofloxacin (61.5%), and amikacin (58%). Imipenem (83.7%) and sulbactam-cefoperazone (81%) were the most effective antibiotics against Acinetobacter isolates.