Two separate cases of abortion due to listeriosis were diagnosed in New York State. One occurred in an Angus cow and the other in a Nubian milking goat. Neither farm reported neurologic signs in affected ruminants. Aerobic culture of the placenta, fetal lung, and fetal abomasal contents grew Listeria monocytogenes. Listeria bacteria grow well in cool temperatures. Multiplication is enhanced in improperly ensiled feed with a pH > 5.0, as well as decaying organic material. Properly ensiling and storing feed, and cleaning up feed bunks and waterers help prevent listeriosis.