AmpC β-lactamases are enzymes that are resistant to β-lactams, such as penicillin and cephalosporin, but not cefoxitin and cefotetan. This study was conducted to characterize AmpC β-lactamases in Enterobacteriaceae. This study included 200 cephalosporin-resistant Gram-negative isolates recovered from different samples between January 2015 and December 2016. The isolates were subjected to phenotypic tests, and those that tested positive were further analyzed by PCR for six AmpC genotypes: ACC, DHA, FOX, CIT, MOX, and EBC. Among the 200 strains, 32% (64) were positive for AmpC β-lactamases by different phenotypic methods. The target genotypes were detected in 20 (10%) of the isolates. Pus was the predominant source of AmpC isolates. Klebsiella pneumoniae (55%) was the most common producer of AmpC β-lactamase. CIT-FOX was the predominant gene type. As there is variation in the prevalence of AmpC β-lactamases in different geographic regions, periodic surveillance and measures to control infection can prevent the spread of these genes.