Farm-reared Coturnix quail less than 3 weeks old showed depression, ruffled feathers, diarrhoea and high mortality. Histological examination revealed basophilic intranuclear inclusion bodies mainly in the digestive tract, and rarely in the liver, kidney, nasal epithelium, conjunctiva and columnar epithelial cells within the mucosa of the bursa of Fabricius. The inclusions were more numerous in the caeca than in the small intestine. Ultrastructurally, they contained many adenovirus-like particles approximately 60 nm in diameter. This is the first evidence of adenoviral inclusions in the glandular epithelium of the gizzard, conjunctiva, plical epithelium of bursa of Fabricius, and mucosal epithelium of small and large intestines in Coturnix quail.