The relationship between gastrin levels and presence of Helicobacter-like organisms (HLO) in dogs with acute or chronic gastritis was investigated. For this purpose, a total of 52 crossbred Kangal Dogs aging 2-5 years were used; including 12 dogs with acute gastritis, 25 dogs with chronic gastritis, and 15 healthy dogs. Blood samples were collected from the vena cephalica. Serum gastrin levels were measured using commercial competitive binding radioimmunoassay. HLO were found in 64%, 58.3%, and 60% of animals with chronic gastritis or acute gastritis, and controls, respectively. The gastrin levels in dogs with chronic gastritis were higher than in those with acute gastritis and controls. There were no significant differences between the gastrin levels in all groups, with regard to HLO positive versus HLO negative dogs. In conclusion, HLO incidence was generally found in high levels in all the dogs. However, HLO did not primarily affect the stomach mucosal damage. In the mean time, there was no relation between the levels of serum gastrin in dogs with gastritis, either being HLO positive or negative. The results of the study showed that higher gastrin levels in dogs with gastritis were related to severe gastric lesions and mucosal damage.