The aim of study was histological evaluation of oviduct and uterus mucosa in case of cystic ovarian degeneration in sows. Materials for evaluations were received after slaughtering of 294 sows at age of 2-5 years. Sows were eliminated breeding and culled due to reproduction disorders: anoestrus after weaning of piglets, return of estrus, small litters and due to age, number of birth, bad condit...