A 50-year-old Japanese woman with Mayer-Rokitansky-Kustner-Hauser syndrome and two pelvic tumors underwent laparotomy. Laparotomy revealed that no torsion of the right ovarian tumor had occurred, with uterine leiomyoma originating from the right side of a rudimentary uterus. Histopathological examination demonstrated leiomyoma of the rudimentary uterus with positive staining for estrogen and progesterone receptors, and mucinous cyst adenoma of the right ovary. Uterine leiomyoma is rare in this syndrome and the present report represents the first published case complicated by ovarian tumor.