Recently, several companies have released H. pylori stool antigen (HpSA) test kits. However, there is little information about the usefulness of HpSA testing for Helicobacter felis, which is the major Helicobacter species in cats. The aim of the present study was to compare diagnostic methods for diagnosis of H. felis with HpSA tests and PCR assay using cat stools or gastric mucosa. Male cats (n=6) were infected with H. felis ATCC 49179 (1.0 × 109 CFU /cat) by intragastric inoculation two times at 3-day intervals, and stool specimens of cats were collected 1, 3, 5, 7, 14, and 21 days after infection for HpSA testing and H. felis-specific PCR. For the results, sensitivities of the HpSA test and PCR analysis were 50.0% and 83.3% respectively. Cats were sacrificed 21 days after H. felis inoculation, and gastric tissues were homogenized. All gastric biopsy specimens were positive based on a rapid urease test (RUT) (6/6, 100%) and PCR (6/6, 100%). Based on these results, the HpSA kit is useful and effective for monitoring H. felis infection using stool specimens. If an HpSA test could be made with H. felis antibodies in the future, its sensitivity could be increased further. Further, PCR assay could be successfully used to detect H. felis in stools. Application of this HpSA kit and PCR assay can be utilized as a non-invasive strategy to identify H. felis in cats.