The aim of the study was to compare 3 stool antigen tests for diagnosis of Helicobacter pylori infection in adult patients with dyspeptic complaints before eradication therapy. We compared 2 enzyme immunoassays (EIAs: Premier Platinum Helicobacter pylori Stool Antigen [HpSA] Plus and Helicobacter pylori Antigen [Hp Ag]) and one immunochromatographic assay (H. pylori fecal antigen test-lateral-flow chromatography) in detecting H. pylori. All the investigated stool antigen tests were made of monoclonal antibodies. We evaluated 168 adult patients with H. pylori infection by using 2 criterion standard methods (histological and rapid urease tests) together. The sensitivity and specificity were 90% and 91%, respectively, for the Premier Platinum HpSA Plus, 77% and 91%, respectively, for the Hp Ag, and 81% and 92%, respectively, for the H. pylori fecal antigen test, respectively. The best agreement between the criterion standard tests and the stool antigen tests used in the study was with the Premier Platinum HpSA Plus. Immunochromatographic assay-based stool antigen test (H. pylori fecal antigen test) was found to be more sensitive than the EIA-based test (Hp Ag). One of the 2 important conclusions obtained from the study was that the Premier Platinum HpSA Plus was found to be the most accurate test for the diagnosis of H. pylori infection in adult dyspeptic patients before eradication therapy, and the other was that monoclonal and high-quality, reliable immunochromatographic assay tests are a good option especially for small hospital laboratories that do not have appropriate equipment for performing the EIA and working on few samples.