Three flocks of turkey hens (16,000 each) between 7 and 12 weeks of age experienced outbreaks of necrotic enteritis. Necropsy revealed a dilated duodenum and jejunum with mucosal surfaces covered with a diphtheritic membrane. Intestinal scrapings showed very few oocysts of Eimeria sp. Histopathological findings were compatible with necrotic enteritis but with deeper, more severe lesions than in broiler chickens. Clostridium perfringens was isolated by anaerobic culture from the intestinal contents. Mortality returned to normal after ampicillin or tetracycline was added to the drinking water.