This is a report of an unusual abortion caused by Pichia pini, assumed to be the sexual stage of an unknown Candida spp, which has never been reported in any case of placentitis or abortion in any domestic animal. Never before reported as pathogenic, this organism caused an acute, diffuse placentitis that was not confined to the region of the cervical star, as would be expected with most cases of equine mycotic placentitis. Various diagnostic procedures were performed on the mare in order to determine the specific pathogenesis and source of this organism, but both remained undetermined. The information obtained from this case may be helpful when future cases of abortion due to Candida spp are investigated.