The Staphylococcus protein A coagglutination test (Sp A COAT) was developed for the diagnosis of rabbit haemorrhagic disease (RHD). Liver, spleen, lungs and kidneys from 176 rabbits dead from viral haemorrhagic disease as well as the same organs from 64 healthy animals were examined by Sp A COAT and haemaglutination test (HAT). The Sp A COAT was specific and considerably more simple to carry out than the HAT, which made it very useful for rapid identification of RHD.