Salivary glands are the most important of the mouth internal secretory. Saliva contains many useful enzymes that help in the digestive process. There are four major salivary glands in cats, including the mandibular, sublingual, parotid, and zygomatic gland. Adenocarcinoma can affect any of these salivary glands in cats, but the major target of this tumor in cats is the parotid gland. Sublingual mass of a cat with clinical sign such as dysphagia, saliva drooling, anorexia and weight loss removed by surgical operation and sent for the histopathological evaluation.In microscopic observation; Tumor of a glandular epithelium was seen. Acinar cells had been established a solid and adenoid pattern. Malignancy signs, including mitotic formation, hyperchromatism and pleomorphism were clearly visible in nucleus of the neoplastic cells. Clinical and histopathological finding reveals an acinic cell adenocarcinoma and in our knowledge, this is the first report on this kind of tumor in salivary gland of a cat.