This study is to explore the clinical value of magnetic resonance imaging (MRI) in the diagnose and the treatment of abdominal wall endometriosis (AWE) with US-guided high-intensity focused ultrasound (USg-HIFU). MRI was performed before and after the USg-HIFU treatment. The information about the clinical characteristics of patients, the characteristics of lesions revealed by MRI, and the outcomes of treatments were collected. We compared results from MRI and color Doppler ultrasound before surgery, as well as the volume and the apparent diffusion coefficient (ADC) values of the lesions before and after USg-HIFU treatment. Thirty lesions in 29 patients were examined. The locations of the 30 AWE lesions were identified by MRI. Their sizes appeared larger in MRI results than that of ultrasound, which had a significant difference (P < 0.05). A total of 27 lesions were evaluated by MRI after USg-HIFU treatment, from which 92.6% (25/27) lesions were of high or slightly high signal on T1-weighted images. They showed annular enhancement and no contrast agent perfusion in the middle of the lesion on post-contrast images, which obviously differ from that in pre-operation. The other two lesions showed iso-intense signal on T1WI with significant enhancement. The mean ADC value of AWE lesions were (1.46±0.30) x10-3 mm2/s and (1.87±0.37) x10-3 mm2/s for pre- and post-HIFU treatment (P < 0.05). MRI is a useful tool for demonstrating the location, size, and concurrent changes of AWE before and after USg-HIFU treatment, which is beneficial for follow-up monitoring or treatments.