This case report describes a two-year-old red and white East Flemish cow with an aggressive angiomyxoma (AA). The cow was presented for examination because of vague complaints: dullness, loss of weight, diarrhea. Rectal examination revealed the presence of multiple large, undefinable masses in the pelvic cavity. The cow died the day after the clinical examination and was autopsied. The histopathological examination revealed an aggressive angiomyxoma. This is, to the best of our knowledge, the first description of an AA in animals.