Campylobacter spp. are a leading cause of human diarrhea. The common source of infection is contaminated food, particularly poultry. From May 2005 to October 2006, 164 samples of poultry obtained from several retail establishments and from different Portuguese producers were analyzed for the presence of Campylobacter spp. A total of 99 Campylobacter strains were isolated and further identified. Susceptibilities for 44 strains were determined for 11 antimicrobial drugs by the agar diffusion technique. According to the minimal inhibitory concentration for 90% of the isolates, resistance to tetracycline, nalidixic acid, rifampicin, erythromycin, vancomycin and penicillin was observed. Sensitivity to gentamycin and chloramphenicol was also demonstrated. According to the antibiotic resistance profiles, the isolates appeared to differ from each other, including those that had been collected at the same period of time and from the same chicken sample.