Objective: To Characterize the type of histopatological lesion associated to Helicobacter spp presence in gastric ulcers of horses. Materials and methods: It was inclueded 25 horses of stomaches with sings of positive ulcers in 2 or more diagnostic test to curvedspiral bacteria Helicobacter spp. A Description of histopathological type of lesion, degree of gastric ulcer was done by hematoxylin-eosin staining. In all samples of gastric ulcers, it determines the degree and type of gastritis associated, and classified into three categories by degree of severity of ulcers, established by the council's Syndrome, Gastric Ulcers in Equines (CEGUS) and the classification of the associated gastritis was performed according to modified Sydney classification, Houston 1995. Variables considered were the total of animals, anatomical area (gastric segment of the mucous one) and age. Results: 30% of the ulcers were grade 1 and 2, 15% of them presented as chronic gastritis, 12.5% chronic active gastritis and a 2.5% chronic eosinofílic gastritis. 57.5% of the signs showed ulcers grade 3 and 4, 25% of them presented as chronic active gastritis, 17.5% chronic eosinofílic gastritis and the 15% chronic gastritis. Only 12.5% of the ulcers were grade 5 and 6, of which 7.5% presented chronic active gastritis, chronic gastritis 2.5% and 2.5% remaining chronic eosinophilic gastritis. Conclusions: The gastric ulcers grade 3 and 4 were the ones belonging to bigger presentation; microscopically the chronic active gastritis and the chronic gastritis were the more observed in the positive signs to Helicobater spp in two or more diagnostic tests.