The salient features of a porcine reproductive and respiratory syndrome (PRRS) epizootic include respiratory disease followed by reproductive failure. The respiratory component is usually recognized first in finishing pigs or in the breeding herd as a mild flu-like disease with a high morbidity for all ages and high mortality in younger pigs. In breeding herds, acute maternal reproductive failure often follows the onset of respiratory disease. PRRS is characterized by a sudden increase in early farrowings, late-term abortions, stillborn and mummified fetuses, weak neonates with high mortality, late returns to estrus, and repeat breeders. No consistent histopathology has been obseived in fetal tissues from epizootics or following experimental infections of susceptible dams. In this report, we describe fetal histopathology associated with an experimental PRRS virus (PRRSV) infection.