This study concerns 180 strains of Enterobacteria isolated at Fann University Teaching Hospital (Dakar, Senegal). The susceptibility to antibiotics was tested by disc diffusion test (antibiogram) and by dilution method determining the minimum inhibitory concentration (MIC). All of the species present more resistant profile to beta-lactams (> 55%); however ceftriaxon and aztreonam present the lower MIC 50 (< 0.06 microgram/ml). Fluoroquinolon inhibits more than 90% of the strains of E. Coli and Proteus. Chloramphenicol is active on Salmonella, but ceftriaxon, aztreonam and the fluoroquinolon present good alternatives. Cotrimoxazole is active only on 54% of Shigella strains.