The presence of extended-spectrum β-lactamases-producing Escherichia coli (ESBL-EC) in food production systems is a public health problem, since they can be transmitted to humans. The aims of this study were to isolate and characterize ESBL-EC from poultry farms located in Argentina. Resistances to β-lactams (first-, third-, and fourth-generation cephalosporins, penicillin), tetracyclines, quinolones, sulfonamides, phosphonates and aminoglycosides were found among the 40 ESBL-EC isolates. In addition, a wide range of antimicrobial resistance profiles were identified. The most frequent accompanying resistance to non-β-lactam antibiotics was tetracycline (97.5 %), followed by ciprofloxacin (82.5 %). All ESBL-EC isolates were multidrug resistant, and were grouped into four bla