Campylobacter fetus subspecies fetus is an opportunist Gram-negative bacillus, which is known to be a cause of systemic infections, mainly in immunocompromised patients. We report a C. fetus bacteremia and cellulitis complicating a venous access port infection in a patient with acquired immunodeficiency syndrome (AIDS). This bacillus seems to have a predilection for the vascular endothelium and its isolation is difficult. Physicians should be aware of C. fetus infection in patients with vascular devices. Microbiologists should accurately isolate this organism from clinical specimens by modifying incubation techniques and performing molecular biology. The prognosis seems to be improved by a prolonged betalactam antibiotic regimen, especially amoxicilline plus clavulanic acid. In HIV infected patients, quinolones that were successful in our case, should be used with caution because of increasing resistance to antibiotics.