Celiac disease (CD) has been associated with non-alcoholic fatty liver disease (NAFLD) and other chronic liver diseases (CLD), such as primary biliary cirrhosis (PBC), autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC). OBJECTIVE To study the frequency of serological markers of CD in patients with NAFLD and CLD and their correlation with duodenal biopsy. METHODS In patients with NAFLD, PBC, AIH and PSC, we studied anti-endomysium (AE) IgA by indirect immunofluorescence and anti-gliadin IgA-IgG (AG) and human anti-tissue transglutaminase (tTG) IgA antibodies by an ELISA technique. Patients with positive serology for at least one marker underwent endoscopy with duodenal biopsies. RESULTS Positive CD markers were found in 9 of 101 patients (8.9%): 7 patients were positive for tTG alone, 1 for AE and AG, and 1 patient for 3 antibodies. Positivity was as follows: 3/38 (7.9%) in NAFLD, 3/44 (6.8%) in PBC, 2/16 (12.5%) in AIH and 1/3 in PSC. Endoscopy was performed in 8 patients, with normal duodenal biopsy in 7 and 1 patient with Marsh stage 1 CD with NAFLD, positive AE and AG. The only patient with 3 positive markers died during the study without undergoing endoscopy. None of the patients had symptoms suggestive of CD. CONCLUSIONS A high prevalence of positive tTG was found in patients with CLD and NAFLD. However, duodenal biopsy should be performed in these patients, given that the results of this procedure were normal in most patients in this study.