During necropsy of a 6-year-old, male African Green monkey (Cercopithecus aethiops), multifocal pale, white to tan areas, 1-2 cm in diameter, were noted in the right lateral lobe, medial lobe, and capsular surface of the liver. Light microscopic examination of the liver revealed numerous spindle cells dispersed within interconnecting, broad bands of collagen, up to 200 microm in width, which often spanned and connected portal areas. A diagnosis of hepatic ductal plate malformation, most closely resembling congenital hepatic fibrosis with von Meyenburg complexes, was made. Few cases of ductal plate malformations in domestic animals are reported in the literature. To our knowledge, this is the first case reported in a nonhuman primate.