The purpose of this study was to establish guidelines for using uterine artery embolization for the treatment of uterine leiomyomas accompanied by adenomyosis in Korea. This study was performed to investigate 1) the effects of uterine embolization on leiomyoma accompanied by adenomyosis, 2) the outcome of uterine embolization according to the embolization materials used, 3) the relationship between the Resistance Index (RI) and the change in uterine volume.We performed a retrospective study on 37 women who had uterine leiomyomas accompanied by adenomyosis. Bilateral uterine artery embolization was performed over a period of 17 months in 37 patients (age range 25 - 65) experiencing pain, hypermenorrhea, urinary frequency, etc. due to leiomyomas. Ultrasound imaging was performed before the procedure and at mean 6.9 months after the procedure.All procedures were technically successful. Mean clinical follow-up time was 12.8 months. Minor complications occurred in 82% patients following the procedure. After follow-up imaging, the median uterine volume decreased by 34.4% and the dominant myoma volume decreased by 86%. There was no statistical difference in the uterine volume reduction and the dominant myoma size reduction, whether the occluding agent was polyvinyl alcohol, polyvinyl alcohol plus gelfoam, or gelfoam, and whether the ultrasound measured Resistance Index value before the procedure was low or high.Primary candidates for uterine artery embolization include those with symptomatic uterine leiomyomas, who no longer desire fertility, but who wish to avoid surgery or are poor surgical risks. According to the results of our study, adenomyosis should not be considered as a contraindication for uterine artery embolization. However, because little data is available about the subsequent reproductive potential following this procedure, it should not be routinely advocated for infertile women. Further investigation is warranted regarding the choice of occluding agent and the role of the Resistance Index.