An outbreak of a neurological disease in pigeons caused by avian paramyxovirus type I occurred in the New York metropolitan area in 1984. It was characterized clinically by head tremors, paresis of the wings and legs, ataxia, torticollis, and loose droppings. Clinical pathologic evaluation revealed anemia and elevated plasma transaminase enzymes. Mortality was virtually 100% in juvenile pigeons, whereas the adults generally experienced much lower morbidity and mortality.