Malignant small intestinal lymphoma may complicate or antedate clinical recognition of celiac sprue, a disorder becoming increasingly diagnosed as a subclinical or occult disease. A 73-yr-old woman with previously resected jejunoileal lymphoma and normal proximal small bowel biopsy specimens was given a high-gluten diet containing 40 g of added gluten daily for 4 wk. This caused small intestinal biopsy abnormalities typical of celiac sprue; the abnormalities resolved 6 wk later with a gluten-free diet. This indicates that latent celiac sprue may be present in some patients with lymphoma and suggests that the association of celiac sprue and lymphoma may be more frequent than is currently appreciated.