Celiac disease (CD) is an autoimmune enteropathy triggered in susceptible individuals by ingestion of gliadin-containing grains. Although the autoimmune process targets mainly the intestinal mucosa, CD can manifest itself with a variety signs and symptoms affecting any organ or tissue. For many years, CD has been underdiagnosed because of poor awareness. However, studies showing a high prevalence of CD in North America, followed by a consensus conference on CD organized by the National Institutes of Health, have fueled a campaign to raise awareness among subspecialists and primary physicians. Nevertheless, guidelines for the diagnosis of CD remain poorly appreciated and many health care professionals remain confused about its proper management. This review is intended to clarify "facts and fantasies" about CD diagnosis.