Hibernoma is a very rare benign tumor and it is suggested to have originated from brown fat tissue, which is responsible for maintaining temperature regulation in hibernating animals and neonatal mammals. Hibernoma is a painless, slowly growing tumor and surgical removal of the mass is considered to be sufficient for treatment. In this case report, we aimed to describe a mesenteric hibernoma in cat. A 13-year-old, Siamese, female cat was presented to the clinic with motility disorder. Blood hemogram values were normal, but total protein (8.3 g / dl), albumin (4.0 g / dl), glucose (158 mg / dl), blood urea nitrogen (43.0 mg / dl) and globulin (4.3 g / dl) ) were found mildly increased. Radiographs showed a well-circumscribed mass nearby the colon and the patient underwent diagnostic laparotomy. At the operation, a mass was detected at the mesenteric margin of the colon. The mass was completely removed and the incision site was omentalized. The mass was routinely proceeded for histopathologic examination, embedded in paraffin blocks and tissue sections of 4 µm thickness were cut and stained with Hematoxylin and Eosin. Furthermore, S-100 and osteopontin immunostaining methods were also performed. Histopathological examination revealed a lobular mass supported by a thin fibrovascular stroma. The neoplastic cells were found round to polygonal surrounded by small capillaries. They had eosinophilic and vacuolar cytoplasm and centrally or eccentrically located nucleus. Immunohistochemical staining showed moderate to severe positive reaction with S-100, while mild reaction with osteopontin was detected. According to histopathologic and immunohistochemical findings, the case was diagnosed as hibernoma. As a result, the present case report showed a mesenteric hibernoma in the cat. Characteristic histopathologic findings led to the diagnosis for hibernoma. Moreover, immunohistochemical findings for S-100 were compatible with the previous studies and weak immune reaction with osteopontin confirmed the benign behavior of the tumor. The motility disorder of the cat was improved by the surgical excision of the mass, and no recurrence has been observed since the post-operative period