A 4.5-year-old Swiss Braunvieh cow was presented to the Department of Farm Animals, University of Zurich, because of severe haematuria. All other clinical findings were within normal ranges. Transrectal ultrasonography revealed a 1 cm × 1 cm echogenic, irregularly-shaped, raised mass in the wall of the urinary bladder. Endoscopy identified the mass as a proliferation, approximately 0.5 cm in diameter, which was bleeding continuously. Thermocautery of the bleeding site was carried out twice five days apart via endoscopy. Clinical signs resolved for the remainder of the cow’s life; she was slaughtered 15 months later because of infertility. Histological examination of the mass revealed a haemangiosarcoma.