Over a 25-month period, we prospectively evaluated 36 patients with symptomatic human immunodeficiency virus disease (including 27 with unexplained chronic diarrhea) by flexible sigmoidoscopy for the presence of Campylobacter-like organisms. No Campylobacter-like organisms were isolated. Campylobacter-like organisms appear to be an uncommon cause of idiopathic chronic diarrhea in symptomatic human immunodeficiency virus disease.