Aims: A crucial mechanism of antibiotic resistance of Escherichia coli (E.coli), a member of gram-negative bacteria that cause infections in intensive care units (ICUs), is beta-lactamase production. This study aims to determine extended-spectrum betalactamase (ESBL) production frequency and antibiotic resistance profile of E.coli strains isolated from blood cultures of adult patients in different intensive ICUs at Erciyes University-Kayseri, Turkey. Materials and methods: This study includes only one E.coli strain per patient. Antibiotic susceptibility test of 81 E.coli strains were performed using Kirby-Bauer disk diffusion method. ESBL-production was determined using double-disk synergy test. Results: A total of 58 (72%) strains were isolated from patients in internal ICUs while 23 (28%) strains were isolated from patients in surgical ICUs. A total of 44 (54.3%) strains were found to produce ESBL with ESBL-production rate of 55.2% in internal ICUs and 52.2% in surgical ICUs. Difference between the presence of ESBL-producing E.coli in male and female patients in ICUs is not statistically significant. 8 (9.8%), 46 (56.8%), 69 (85.2%), 22 (27.2%), and 44 (54.3%) and zero strains were resistant to amikacine, ciprofloxacine, ampicillin, piperacillin-tazobactam, cefotaxime, and imipenem, respectively, and no strains were resistant to imipenenm. Resistance to amikacin, ciprofloxacin, ampicillin and cefotaxime in ESBL producing strains were significantly higher than ESBL non-producing strains (p<0.05). Piperacillin-tazobactam resistance ratio for E.coli strains isolated from surgical ICUs was found to be significantly greater than those isolated from internal ICUs (p<0.05). Despite higher ratios of ESBL-production of E.coli strains, carbapenem resistance was not gratifyingly determined in the ICUs. Conclusion: Early diagnosis and immediate treatment of nosocomial bacteremia are important for patients' survival. Therefore, monitoring antibiotic susceptibility profiles of isolated microorganisms will guide clinicians for controlling infections.