OBJECTIVE: This study aimed to assess the effectiveness of conventional magnetic resonance imaging (MRI) combined with three-dimensional (3D) ultrasound for the preoperative prediction of nonperfused volume ratio (NPVR) in uterine fibroids after high-intensity focused ultrasound (HIFU) ablation. MATERIALS AND METHODS: In total, 178 patients who had undergone HIFU ablation therapy for uterine fibroids between July 2021 and August 2023 were enrolled. Baseline clinical, MRI, and 3D ultrasound parameters collected before and after HIFU ablation were analyzed. Multiple linear regression models were constructed for conventional MRI parameters alone and for combined MRI-3D ultrasound parameters to predict NPVR. Paired-sample RESULTS: The combined MRI-3D ultrasound model outperformed the conventional MRI model, with adjusted CONCLUSIONS: 3D ultrasound provided essential information for screening fibroids and predicting NPVR before HIFU ablation, serving as a valuable supplement to MRI. The combined MRI-3D ultrasound model shows promise for the preoperative prediction of NPVR in patients with uterine fibroids treated with HIFU and may offer substantial clinical value.