The purpose of this study was to assess the epidemiology of local enterobacterial susceptibility to antibiotics. Between 1 January, 1998, and 31 December, 2001, we studied the sensitivity of 2,238 Enterobacteria to 26 different antibiotic agents in northern Lebanon, in the Microbiology department and Laboratory of the Islami Hospital, Tripoli, Lebanon. We used the diffusion disk method and complied with the guidelines of the French Microbiology Society antibiogram committee. Urinary samples were the most frequent source (67.5%), followed by blood cultures (12.7%). The dominant species in blood cultures was S. typhi (44.7%). We found 194 strains that produced extended-spectrum beta lactamases (ESBL), with the highest prevalence in Serratia spp. (44.3%), followed by Klebsiella pneumoniae (23.7%), Escherichia coli (20.7%) and Klebsiella oxytoca (11.3%). The global susceptibility of these strains to aminopenicillin was 15%; it reached 30% when combined with clavulanic acid. Susceptibility of the ESBL strains to these agents was 0%. The global susceptibility (and that of the ESBL strains, when greater than 0%) to other antibiotics was as follows: ticarcillin 38.5%, piperacillin 38.5%, piperacillin-tazobactam 88% (64%), imipenem 99.4%, (100%), cefalexin 41%, cefoxitin 65% (40.3%), cefuroxime 75%, amikacin 89%, chloramphenicol 30%, gentamicin 78% (42%), tetracycline 28% (16%), minocycline 30% (18.4%), colistin 67% (75%), nitrofuran 40% (45%), cotrimoxazol 40% (13%), nalidixic acid 53% (5.6%), pefloxacin 63% (23%), ciprofloxacin 71% (39%), and levofloxacin 72% (47%).