In a first experiment, 28 specific pathogen-free chickens aged 3 weeks showed clinical signs 1 to 5 days after intramuscular inoculation with Erysipelothrix rhusiopathiae. Twelve of 28 birds died 2 to 4 days after inoculation. Macroscopically, the liver, spleen and kidneys were seen to be enlarged and congested. Histologically, fibrinous thrombus formation, seen in the hepatic sinusoids, renal glomerular capillaries and small pulmonary blood vessels, was a characteristic feature. In addition, the liver showed marked congestion, increase of mononuclear cells and heterophils in the sinusoids, hyperplasia of sinusoidal lining cells, and vacuolar changes in hepatic cells. The spleen showed fibrinous exudation of the lymphoid follicles and ellipsoids with lymphocytic depletion, and hyperplasia of ellipsoidal reticular cells. There was oedema, congestion and cellular infiltration in the interstitium of the kidney. The bursa of Fabricius and thymus showed marked lymphocytic depletion. In a second experiment, the blood chemical values (uric acid, glutamic-oxalacetic transaminase, lactate dehydrogenase and γ-glutamyl transpeptidase) of birds inoculated intramuscularly with E. rhusiopathiae were significantly higher than those of uninfected controls. The blood prothrombin times and activated partial thromboplastin times of the inoculated group were significantly greater than those of the control group. The pathological and haematological findings demonstrated that E. rhusiopathiae induced disseminated intravascular coagulation in the chickens.