Production of Extended Spectrum Beta Lactamase (ESBL) enzymes is one of the main reasons for drug resistance in Escherichia coli (E. coli) isolates. The aim of this study was to determine the ESBL producing E. coli isolates in the blood culture of patients in hospitals and medical centers in Tabriz, Iran. In this descriptive cross-sectional study, 200 isolates of E. coli from blood specimens in hospitals and medical centers were investigated from December 2018 to May 2019. The production of ESBLs was confirmed using the combined disc method and antimicrobial susceptibility test. Out of 200 isolates, 100 isolates (50 %) were able to produce ESBL. The highest antibiotic resistance of isolates (100 %) was to ceftriaxone, cefotaxime, cefixime and cefuroxime. The highest antimicrobial susceptibility was also observed to amikacin (12 %), meropenem (6 %) and imipenem (2 %), respectively. The results of this study showed the high resistance of E. coli isolates especially ESBL producing strains to different antibiotics. Given the relatively high prevalence of the ESBL producing E. coli strains and their resistance to common antibiotics, effective control strategies such as the restricted use of broad spectrum cephalosporins should be implemented.