We report the case of a 45-yr-old white man, investigated for chronic diarrhea, malabsorption and weight loss associated with sicca syndrome. Endoscopic and x-ray examinations showed normal macroscopic mucosa in gastrointestinal tract (GIT). Immunohistochemistry showed diffuse polyclonal T cell lymphocytes infiltrating either epithelium and lamina propria in GIT. There was no villous atrophy in the jejunum and ileum. Corticosteroids, azathioprine, and cyclosporine failed to improve symptoms. Monthly intravenous cyclophosphamide administered over 1 yr, stopped the diarrhea and weight loss. The patient is free of symptoms up to a 5-yr follow-up.