Central or peripheral nervous system complications are occasionally observed in adult patients with celiac disease. Several mechanisms have been proposed including vitamin deficiency, vascular inflammation and a direct effect of gluten intolerance. Typical nerve fiber damage due to demyelinization has been suggested. We observed a 65-year old woman with a right peroneal nerve palsy superimposed on a diffuse peripheral neuropathy who was found to have folic acid deficiency which in turn led to the diagnosis of adult celiac disease. Electrophysiological and histological studies demonstrated a predominantly demyelinating peripheral neuropathy which responded first to parenteral folic acid supplementation and second to a gluten-free diet. The mechanisms of peripheral nerve damage in adult celiac disease are briefly discussed and the possible role of folic acid deficiency is emphasized.