The aims of our study were to determinate the prevalence of helicobacter in a population of Slovenian dogs, to characterize the intensity of infection and to find out if the epidemiological parameters i. e. age, feeding regimen, gender, breed, location and indoor/outdoor living conditions have any influence on infection and the intensity of infection. A total of 185 randomly chosen dogs from all parts of Slovenia, at ages from 9 days to 15 years, of both genders and 44 different breeds, without any gastrointestinal disorders, were included in our study. Helicobacter were detected in stomachs of 92.4% of dogs. We determined a mild infection in 17.3% of dogs, a moderate infection in 48.1%, and a strong infection in 27% of dogs. Studying epidemiological parameters and their effects on infection we concluded that age and feeding regimen affect the infection and the intensity of infection, whereas gender, breed, location and indoor/ outdoor living conditions do not.