This study investigated the effect of enrofloxacin (ENR) administration on the prevalence and antimicrobial resistance ofE. coli,Salmonella, andCampylobacterisolated from broiler chickens under field conditions. The isolation rate ofSalmonellawas significantly lower (p< 0.05) on farms that administered ENR (6.4%) than on farms that did not (11.6%). TheCampylobacterisolation rate was significantly higher (p< 0.05) in farms that administered ENR (6.7%) than in farms that did not (3.3%). The ratio of resistance to ENR was significantly higher (p< 0.05) inE. coliisolates from farms that used ENR (88.1%) than farms that did not (78.0%). The respective ratio of resistance to ampicillin (40.5% vs. 17.9%), chloramphenicol (38.0% vs. 12.5%), tetracycline (63.3% vs. 23.2%), and trimethoprim/sulfamethoxazole (48.1% vs. 28.6%) and the ratio of intermediate resistance to ENR (67.1% vs. 48.2%) were significantly higher (p< 0.05) inSalmonellaisolates from the farms that used ENR than farms that did not. In conclusion, the use of ENR at broiler farms was an important factor in decreasing the prevalence ofSalmonellabut notCampylobacterand caused ENR resistance amongE. coliandSalmonellabut notCampylobacter. Exposure to ENR could have a co-selective effect on antimicrobial resistance in enteric bacteria in the field.