Campylobacter is now known to be a major cause of gastrointestinal illness throughout the world. There are seven species known to be associated with enteritis, and it is likely that more will be described. Campylobacter jejuni is responsible for more than 95 per cent of the cases of diarrhea due to Campylobacter. Contaminated food products are the major source of infection. The clinical illness usually involves diarrhea, abdominal pain, and other constitutional symptoms. An accurate diagnosis of Campylobacter enteritis is made when the organism is cultured from the patient's stool. Selective media are widely available, and the isolation of C. jejuni is not difficult. Although erythromycin and the quinolones have good in vitro activity against C. jejuni, antibiotic therapy generally is not indicated.