A deceased 10-yr-old male ostrich was diagnosed with severe necrotizing enteritis and septicemia. The bird was inappetent for 3 wk and had neurologic signs 2 days prior to death. Macroscopically, no significant lesions were noted aside from congestion of the liver, kidneys, and spleen. Histopathology revealed severe fibrinonecrotic enteritis associated with large numbers of gram-negative bacteria, multifocal fibrinoid necrosis in portal arteries, accumulation of fibrin in hepatic sinusoids, myocardial degeneration, and necrosis. There was also squamous metaplasia in the glands of the esophagus and external ears. A gram-negative rod was isolated in pure culture from intestine, liver, lungs, and trachea and identified as an Aeromonas species. The concentration of vitamin A in the liver was extremely low. The lesions seen in the intestine and liver and the isolation of an Aeromonas sp. from various tissues strongly suggest that this bacterium was the cause of the necrotizing enteritis, septicemia, and death of this ostrich. Vitamin A deficiency might have predisposed the bird to the Aeromonas infection.