A substantial minority of patients with coeliac disease (estimated at anything between 7 and 30%) fail to respond to treatment with a gluten-free diet. Non-responsiveness may be primary, that is when the patient fails to respond to treatment following initial diagnosis, or secondary, when a patient who has previously had a documented response to gluten exclusion becomes non-responsive to therapy. The commonest cause of non-responsiveness is continued gluten ingestion, either voluntary or inadvertent. Other causes to be considered include intolerances to dietary constituents other than gluten (e.g. milk, soya), pancreatic insufficiency, enteropathy-associated T-cell lymphoma and ulcerative jejunitis. There is some evidence that ulcerative jejunitis is, in fact, a manifestation of lymphoma. The most important steps in the management of the non-responsive coeliac patient are (a) to determine whether the patient is indeed coeliac, (b) to exclude lymphoma and (c) to establish the cause of the non-responsiveness. In those coeliac patients with no demonstrable cause for non-responsiveness, a variety of therapeutic stratagems (mostly based on small, uncontrolled studies) have been described; these include elimination diets, dietary supplementation with zinc and copper, and pharmacological therapy in the form of steroids, azathioprine and cyclosporin. In a minority of non-responsive patients, the clinical course is characterized by a rapid decline, and total parenteral nutrition is required. None of the therapies described above has been subjected to rigorous controlled studies. The precise mechanisms of non-responsiveness in coeliac patients need to be unravelled before rational therapeutic approaches can be established.