In this study, investigation of biofilm formation levels of clinically acquired Escherichia coli strains and exami- nation of each E. coli strains’ clinical information such as clinical material and service units according to their biofilm formation results were determined. In this respect, according to our results; E. coli strains are grouped as 31% Strong Biofilm Former (SBF), 27% Intermediate Biofilm Former (IBF), 25 % Weak Biofilm Former (WBF) and 17% None Biofilm Former (NBF). In addition to this, clinical materials of wound and urine were found as the most frequent clinical materials from which strong biofilm Former E. coli strains isolated. Besides, urology and cardiology were found as the most SBF isolated service units. Apart from these, E. coli strains were mostly isolated from urinary tract infections and from women who are at the period of post-menopausal. Lastly, the antibiotic susceptibility patterns were investigated and the greatest susceptibility was observed against amika- cin and the least susceptibility was observed against trimethoprim/sulfamethoxazole. Accordingly, NBF strains of E. coli were more susceptible to eight antibiotics than Strong Biofilm Former (SBF) strains.