In this study, we aimed to investigate the susceptibility of Gram negative bacteria against to cefepime, is a novel one of the fourth generation cephalosporins, by using disc diffusion method. Two hundred thirty seven of total 255 (93%) Gram negative bacteria were susceptible to cefepime. Susceptibility of cefepime in Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter spp were 97%, 84%, 82% and 78%, respectively. All of Klebsiella oxytoca, Morganella morganii, Serratia marcescens, Proteus vulgaris and Proteus mirabilis strains were susceptible to cefepime. The least susceptibility of cefepime was observed for Enterobacter spp (78%).