The objective of this study was to determine the cause and prevalence of bovine abortion and stillbirth in Kyungi-do area. Seventy three bovine fetuses were collected from farms and submitted to the College of Veterinary Medicine, Seoul National University. Submitted fetuses were evaluated during a 4-month period (July to November, 1999) for pathological lesion, tissue protozoa, bacteria and viral infection. The average proportion of abortions was decreased with parity in 73 abortion heifers and cows. Monthly incidence rate of bovine abortion was not different in this study. In fetuses from 90 to 282 days gestation, the majority were between 150 and 250 days gestation(58%). The cause of abortion or stillbirth was determined in 51% of the cases examined. In 15(21%) of the fetus, neosporosis were diagnosed by pathological findings. In three (4%) additional fetuses in three additional fetuses, suspected Neosporosis by pathological lesion, and in 3 (4%) fetuses examined Neopsorosis were diagnosed in 15 feturses and in 3 fetuses, Neosporosis was suspected by pathological legions. Neosporosis / viral infection were diagnosed in three additional fetuses). Miscellaneous bacterial infection, BVDV, iatrogenic cause, Neosporosis / IBRV / BVDV, miscellaneous viral, IBRV/BVDV and others were 3(4%), 3(4%), 2(3%), 2(3%), 1(1%), 1(%) and 9(12%) respectively. The cause and incidence of bovine abortion in different area in Kyungi-do was not different in this study.