Two cases of retroperitoneal edema surrounding the left ovarian vein that were associated with large uterine leiomyoma are presented. This finding was not associated with any specific lateralizing symptoms or with any evidence of malignancy. One patient underwent hysterectomy with surgical exploration of the retroperitoneum that confirmed the absence of malignancy. The CT and MR findings in this entity are described and possible etiological mechanisms discussed. Recognition that large leiomyoma can be associated with benign retroperitoneal edema may help avoid inappropriate management.