Two adult Masai ostriches in a zoological collection became recumbent. The birds could not raise the neck or the head, had difficulties in breathing, and died eight and 13 days, respectively, after the first clinical signs appeared. On post mortem examination the heart had a globous appearance accompanied by gelatinous atrophy. The lungs were hyperaemic and oedematic, while the intestines had prominent haemorrhages in their mucosa. The liver and kidney were enlarged, and the former had also necrotic foci. Smears taken from the hyperaemic regions of the intestines and the necrotic foci of the liver were positive to Clostridium chauvoei after staining with specific fluorescein-labelled antiserum. No other pathogenic agents were identified or isolated from these birds. This report appears to be the first of a pathogenic condition associated with C chauvoei in an avian species.