A patient with cirrhosis and ascites who developed spontaneous bacterial peritonitis due to Campylobacter fetus is described herein. This organism has been increasingly associated with bacteremia and localized infections in patients with cirrhosis and other immunocompromised states, but spontaneous bacterial peritonitis has been rarely reported. We review Campylobacter fetus infections and their relationship to development of spontaneous bacterial peritonitis, and we emphasize that prolonged antimicrobial therapy is required.