Villous atrophy of the terminal ileum is usually secondary to celiac disease or other diseases. Very few cases of primary ileal villous atrophy have been reported in the literature. We report here the case of a 37-year-old man with chronic diarrhea since childhood without features of malabsorption. The macroscopic and microscopic appearance of the duodenal, ileal and colonic mucosae at endoscopy and contrast radiography of the small bowel was normal. Ileal lesions consisted of total villous atrophy. Search for antinuclear antibodies, anti-endomysium and anti-gliadin IgA and IgG and HIV serology were negative. Serum immunoglobulin level was normal. Diarrhea resolved under treatment with colestyramine.