Gastric tumors are rare in dogs and cats but should always be considered, particularly in older dogs with chronic vomiting. The most common gastric tumor in dogs is carcinoma, although lymphoma is rare. Breeds that seem to be predisposed to gastric carcinoma are the Rough Collie, Staffordshire Terrier, and Belgian Shepherd. Lymphoma is the most common gastric malignancy in cats. Contrast radiographic examination and endoscopy are the elective procedures of choice for the diagnosis of these conditions. Biopsy is essential to confirm the diagnosis. Surgery is the only potentially curative modality for localized gastric carcinoma. Chemotherapy alone or following surgery is the elective treatment of choice for gastric lymphoma in dogs and cats. The prognosis is poor for both types of tumor, but prolonged survival times in individual animals are possible.