Uterine arterial embolisation in the management of fibroids can only be carried out if the preoperative diagnosis has been made accurately. It is particularly important to exclude adenomyosis or malignancies. In medicine the gold standard is a histological diagnosis. We have used transvaginal ultrasound guided gun biopsy of the uterus or ovaries in the office setting, in order to obtain a tissue sample for histological conformation of the preliminary ultrasound findings. Twenty two patients scheduled to undergo uterine arterial embolisation with an equivocal ultrasound diagnosis were biopsied. In eight (36.4%) patients the preliminary ultrasound diagnosis of adenomyosis was confirmed histologically, and in nine (40.9%) patients the ultrasound diagnosis of leiomyoma was confirmed histologically. In two patients the ultrasound diagnosis of a benign ovarian mass was confirmed histologically. In the remaining three (13.6%) patients, the preliminary ultrasound diagnosis was incorrect. One patient was thought to have a leiomyoma where the histology was of a benign adenomatoid tumor, another patient was thought to have a sarcoma where the histology was of a leiomyoma, and one patient thought to have adenomyosis was shown to have a normal myometrium. There were no procedure related complications. This simple office based technique is safe, and effective.