Rectovaginal injuries can result in subsequent infertility in cow. In a retrospective study, records of 147 Holstein cows with evidence of rectovaginal injuries were reviewed to determine their effects on fertility. This study was conducted in a large dairy(typical herd size 1420 cows) in Tehran between the years 1993 and 1996. Period prevalencec were 0.4 % fistula, 1.9 % laceration (third degree), 5.4 % pneumovagina, 1.5 % urovagina and 0.8 % mixed injuries. The highest ocurrence was among first-calf heifers (66 %). Thirteen cows repealed the same condition in the subsequent calving. Eighty seven first-calf heifers without the history of retained placenta were selected of which,73 cows were considered as operated group, of which 61 cases (83.6%) became pregnant. Of 14 unoperated controls, 11 cows (78.6 %) became pregnant. Pregnancy percentage in delaye-operated group decreased gradually (in days 1-45, 46-90, 9 1-120 and> 120 were 85.9, 82.4, 75 and 73.7 % respectively). It was concluded that rectovaginal injuries had a negative effect on reproductive performance of the cows. Comparison between operated and unoperated first-calf heifers showed significant increases in the number of days to first service(228.6 228.6 vs 164.5 days), number of days open (13l.lvs 93.4 days) and the calving interval (476.8 vs 409.9 days) (p
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