Background: Urinary tract infection (UTI) is one of the most common hospital acquired and community acquired infections. Escherichia coli (E. coli) are the most prevalent bacteria causing UTI. As a result of the extensive use of β-lactam antibiotics in the clinical practice, extended spectrum β-lactamases (ESBLs) have emerged. E. coli is among the most prevalent ESBL producing bacteria. Objectives are to detect antibiotic sensitivity and ESBL production of E. coli isolates in hospital acquired and community acquired UTIs in Tanta University Hospital and to evaluate different methods for phenotypic confirmation of ESBL production. Methodology: E. coli isolates were identified by Conventional biochemical reactions. The isolates were tested for antibiotic sensitivity by the disc diffusion method. Different methods for phenotypic confirmation of ESBL production were evaluated. Results: E.coli was the causative organism in 58% of cases of community acquired UTI and 30% of cases of hospital acquired UTI. It was found that 37 of E.coli isolates were ESBL producers. Among the phenotypic confirmatory methods which were evaluated in our study, it was found that double disk synergy detected the least number of ESBL producing E.coli isolates. Conclusions: incidence of ESBL production among E. coli isolates is high. Periodical detection and monitoring of antimicrobial susceptibility of ESBL isolates, and rotating the use of effective antimicrobial drugs are recommended to decrease the risk of high antibiotic resistance rate.