question: Coronavirus-induced porcine epidemic diarrhoea (PED) was diagnosed in two swine herds. The causal agent was demonstrated in intestinal contents by electron microscopy and identified by immunoelectron microscopy using specific immune serum to the reference strain PED-CV77. Experimental transmission to hysterectomy-derived, colostrum-deprived piglets with an intestinal contents filtrate was successful. The virus was demonstrable by electron microscopy in the intestinal contents between 12th hour and 4th day, and in small intestinal epithelial cells 18 hours after infection. Scanning electron microscopy revealed shortening and fusion of villi of small intestinal mucosa.