Aim. To define the value of a new enzyme immunoassay in determining the level of anti-deamidated gliadin peptide (DGP) antibodies (Abs) in the diagnosis of celiac disease. Subjects and methods. One hundred and twenty-four patients treated at the Department of Intestinal Pathology, Central Research Institute of Gastroenterology, were examined. Enzyme-linked immunosorbent assay (ELISA) was employed to determine Abs to tissue transglutaminase (tTG) and DGP of the IgA and IgG classes in the sera of all the patients. The diagnosis of celiac disease was verified by the histological examination of small bowel mucosa biopsy specimens. Results. The examinees were divided into 3 groups: 1) 27 patients first diagnosed with celiac disease; 2) 40 patients keeping a gluten-free diet (GFD); 3) 57 patients with other gastrointestinal diseases (a comparison group). In the patients first diagnosed with celiac disease, the detection rate of elevated titers of anti-tTG and anti-DGP Abs in the IgA class was equal and constituted 92.5%; that in the IgG class was 96.2 and 55.5%, respectively. The comparison group showed an increase in the DGP levels in the IgA and IgG classes in 4 (7%) patients and a rise in tTG concentrations in the IgA and IgG classes was seen in only 2 (3.5%) patients. Conclusion. In the patents first diagnosed with celiac disease, the detection rate of elevated levels of anti-DGP Abs in the IgA and IgG classes is 92.5 and 96.2%, respectively, and significantly indifferent from that of IgA and IgG anti-tTG Abs. The patients keeping GFD displayed a reduction in anti-DGP Abs. The high detection rate of IgA anti-DGP Abs in the patients first diagnosed with celiac disease allows this method to be recommended for immunological diagnosis of this disease in adults.