SummaryDifferent species of gastric Helicobacter-Like Organisms (GHLO) reported from dogs' stomach. The aim of present study was to morphological evaluation of gastric Helicobacter spp. in fresh gastric samples of naturally infected dogs. Thirty two gastric samples of the stray dog were taken at necropsy. The specimens were used for rapid urease test, light microscopy, scanning electron microscopy (SEM) and polymerase chain reaction (PCR). Light microscopy examination confirmed the presence of GHLO in 90.5% of stray dogs. 87.5% and 94% of gastric samples were positive in rapid urease test and PCR, respectively. Four distinguishable Helicobacter organisms were confirmed by SEM. Three strains of these organisms were inditified as H. felis, candidatus H. heilmanii and H. bizzozeronii because of their apparent morphological differences and PCR results. The last strain of these bacteria was not distinguishable with routine studies. The large-scale studies with fast and simple recognition methods are recommended to confirm the different types of canine gastric Helicobacter. The results of present study showed further investigation in canine GHLO is required because new species of Helicobacter reported.