A two-year-old male peacock (Pavo cristatus) showed acute watery green diarrhea, followed by neurological signs including torticollis and muscular tremor. By the hemagglutination inhibition test for detecting the antibody against the Newcastle disease virus (NDV), the peacock serum inhibited the agglutination of chicken red blood cells. Grossly distinctive hemorrhagic lesions were found in the mucosa of proventiculus and intestine and lung. The spleen revealed multiple variable sized necrotic foci. Histologically, the mucosa of gastrointestinal track had hemorrhagic lesions and some of them underwent ulceration. The spleen exhibited multiple variable sized necrotic foci in which fibrin exudation was marked. Central nervous system had mild non-suppulative menin-goencephalitis consisting of vasculitis, perivascular hemorrhage, gliosis and meningitis. The cells particularly in the cerebellum were degenerative to necrotic. Some of these nerve cells revealed characteristic peripheral chromatolysis. From the present serological and pathological findings, it is suggested that NDV causing death of peacock was velogenic viscerotropic strain. This is the first report of the occurrence of velogenic viscerotropic NDV in an adult peacock in Korea.