This was a single-site cohort study to evaluate the safety of a new transcervical device (VizAblate™) combining real-time intrauterine sonography with radiofrequency (RF) ablation for the treatment of fibroids. Nineteen women with uterine fibroids received treatment with the VizAblate System in a closed abdomen setting prior to hysterectomy. Twelve of these subjects underwent an immediate abdominal hysterectomy after radiofrequency ablation (acute group), while the remaining seven underwent hysterectomy on post-ablation days 16 and 17 (subacute group). Uteri were sectioned and stained with the viability stain triphenyltetrazolium chloride (TTC) to quantify fibroid ablation dimensions and assess the serosa for thermal injury. Subjects in the subacute group were treated with the VizAblate System under conscious sedation; they provided pain and tolerability data for the interval from ablation through hysterectomy, and indicated overall procedural satisfaction. Twenty-two ablations ranging from 1.8 to 36.2 cm 3 were created among 19 subjects within 20 fibroids and one region of adenomyosis. There were no complications or thermal serosal injury. For subjects in the subacute group receiving one ablation, the mean total procedure time was 25.8 ± 6.0 min (range 18–32 min). All subjects in the subacute group were discharged within 2 h of the VizAblate procedure. For fibroids ≤ 5 cm, 67.2% ± 27.0% of the fibroid volume was ablated (range 15–100%; median 75%). Transcervical RF ablation of fibroids under intrauterine sonographic guidance with the VizAblate system can be accomplished with a high degree of reliability and without adverse events.