Pathologo-anatomic picture of the disease caused by Pasteurella pseudotuberculosis in 20 red monkeys and 2 green marmosets are described. An intestinal form of the infection was observed in the majority of the animals. The main manifestations of pseudotuberculosis in the monkeys were: lesions of the gastro-intestinal tract in the form of grave, occasionally ulcerative enterocolitis; enlargement of the spleen with the presence therein and in the liver of necroses and low granulomatous reaction; enlargement of the lymph nodes, mesenteric in particular, with the characteristic macrophagal reaction in them; impairment of the blood circulation in organs with haemorrhages and necroses, with colonies of microbes in tissues. In the course of bacteriological investigations the pathogen Pasteurella pseudotuberculosis was isolated from the perished animals.