A patient had common variable immunodeficiency, chronic malabsorption, and Campylobacter jejuni infection. Infection was diagnosed by jejunal aspiration. A follow-up jejunal aspirate was culture positive at the same time that a stool culture was negative. Infection resulted in worsening of chronic diarrhea, but it was not associated with clinical features of colitis or proctitis. The duration of infection was prolonged and initial antimicrobial therapy was ineffective. Single drug therapy with erythromycin ethylsuccinate and then chloramphenicol led to the emergence of resistant organisms. After five months of bacterial excretion, combination therapy with metronidazole and neomycin sulfate eliminated the organism. This case emphasizes that the clinical manifestations and response to therapy of C jejuni infection can be altered in immunodeficient patients.