In this case, it was aimed to investigate the clinical and pathological aspects of fibromatosis which make difficult rectal examination due tomultiple tumoral masses observed in a 4-year-old Simmental–breed at rectum. Period of after the birth, the masses were seen around therectal area of the cow when rectal examination was carried out. The number and volume of masses increased with time.The shapes of masseswere round and oval and the largest size were 6.5 cm in diameter and 4 x 3 x 1.4 cm respectively. Totally 14 masses, covered with skin andmucosal membrane were found. Cut surface were whitish colored and solid-flexible in consistency. The tissues were fixed with 10% bufferedformaldehyde and embedded in paraffin and sections with a thickness of 5 μm were stained with hematoxylen-eosin (H&E) and Van Giesonand immunohistochemical (IHC) with cytokeratin and vimentin.Tumor tissue in H&E sections consisted of fibroblasts and fibrocytes locatedin the typical herringbonepattern. Tumoral cells were vimentin-positive and cytokeratin-negative in IHC staining.Macroscopic, microscopicand IHC findings, in this case, were found to be consistent with the presence of fibromatosis in the caudal rectum.