By this study, the presence of H. pylori in the gastric mucosa samples of cats and dogs were investigated by culture, microscopy, direct urease test, Dot-Immunobinding Assay (DIA) and Polymerase Chain Reaction (PCR). For this reason, biopsy samples from antrum of 41 dogs and from corpus and cardia of 40 dogs by endoscopy and from antrum, corpus, cardia of 9 dogs and 2 cats by necropsy were taken three times. Blood samples from the 39 dogs were taken for serological examination by DIA test. Neither H. pylori nor any other Helicobacter spp. could be isolated from the animals used in the study. Positivity for Helicobacter spp. by the direct urease test were found in 59 (38 %) of 154 gastric mucosa samples. All serum samples of dogs were found to be positive by DIA. Mucosa samples of the dogs (n=148) and cats (n=6) were analysed using CAM-2 and CAM-4 primers by PCR, and produced only one positive result from a dog corpus. In conclusion, this study reports that the gastric Helicobacter spp. which can be strains that cannot be cultured found in the stomach of dogs and cats.