A young, captive-bred Harris's hawk, Parabuteo unicinctus, exhibited high fever and apparent paralysis of one leg shortly before death. Postmortem examination revealed milky white kidneys, white crystalline deposits in the pericardial sack, and white crystals in one intertarsal joint. Uric acid concentrations determined for the kidneys, heart muscle, skeletal muscle, and scrapings from the pericardial sack (20 mg) and intertarsal joint (2 mg) were, respectively, 12,200, 200, 110, 20,700, and 43,000 mg/100 g tissue. Compared with a healthy hawk, concentrations were elevated by a factor of 50 in the kidneys, 37 in skeletal muscle, and 18 in cardiac muscle.