Introduction: Some strains of Escherichia coli and Klebsiella pneumoniae produce Extended Spectrum Beta-Lactamases (ESBL) may be responsible for various infections such as urinary infections. These Sick people are treated in the very serious cases by association antibiotics to class to betalactamins, aminosids and quinolons. But proliferation of multi-drug resistant strains involves decreasing therapeutic success. That’s why epidemiological study must be done in all laboratories of bacteriology. Purpose: The aim of the study was to research the resistance phenotypes of our E. coli and K. pneumoniae ESBL strains compared to others families of antibiotics. Material and methods: Thirty two (32) Extended Spectrum betalactamases E. coli and K. pneumoniae strains isolated from either hospitalized patients or sick people who came for consultation were studied. Susceptibility to antimicrobial agents was determined using an antibiotic disk (Bio-Rad) diffusion method on Mueller-Hinton agar (Bio-Rad). The results were interpreted according to the Standards of the French Antibiogram Committee (CA-SFM). Results: The study showed that most of these strains were multi-drug resistant. They were resistant to many beta-lactamines antibiotics. E. coli strains were also resistant at 70,34% to aminosids, at 96,72% to quinolons, at 58,3% to cotrimoxazol, at 26,1% to chloramphénicol and at 21,4% to colistin ; about K. pneumoniae, they were resistant at 72,6% to aminosids, at 88,95% to quinolons, at 86,7% to cotrimoxazol, at 44,4% to chloramphénicol and at 25% to colistin. But all these strains were sensitive at 100% to l’imipenem.