Objective: To assess the safety and efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation for uterine fibroids and adenomyosis. Methods: This study included 1807 patients (uterine fibroids, n = 918; adenomyosis, n = 889). Treatment was performed using the model Haifu JC Focused Ultrasound Tumor Therapeutic System under real-time ultrasound guidance. The volume change and clinical symptom improvement based on symptom severity score (SSS) and quality of life (UFS-QOL) score after treatment were evaluated. Results: At three, six, and 12 months after treatment, means ± SD for uterine fibroid volumes were 79.87 ± 74.81, 66.20 ± 81.49, and 46.23 ± 54.7 (p < 0.001 ); 24.74 ± 16.28, 23.72 ± 15.05, and 24.94 ± 15.15 for SSSs (p < 0.001); and 79.42 ± 17.99, 81.69 ± 18.55, and 81.20 ± 15.96 for UFS-QOL scores (p < 0.001). At three, six, and 12 months after treatment, means ± SD for uterine volumes of adenomyosis uteri were 137.49 ± 76.94, 122.03 ± 73.56, and 98.91 ± 60.92 (p < 0.001); 24.87 ± 16.38, 23.58 ± 15.04, and 24.98 ± 15.11 for SSSs (p < 0.001), and 79.64 ± 17.91, 81.59 ± 18.44, and 81.35 ± 15.88 for UFS-QOL scores (p < 0.001) . The complication rate was 6.3% (113/1807), including two cases of small bowel perforation at two and five days after treatment. Laparoscopic surgeries of the small bowel were successful. Conclusion: USgHIFU is an effective, noninvasive modality for uterine fibroids and adenomyosis; it results in reduced volume, symptom improvement, and higher UFS-QOL scores. All adverse events were manageable with acceptable therapeutic outcomes.