In 2014, the American Association of Oral and Maxillofacial Surgery recommended surgical treatment for medication-related osteonecrosis of the jaw (MRONJ) patients classified as stage 3 or those with mobile segments of bony sequestrum. However, there is limited information regarding the healing mechanism in MRONJ surgical treatments. This study aimed to retrospectively elucidate clinical outcomes of the surgical treatment of MRONJ patients. This study included 26 patients (7 men, 19 women; age: 42-92 years; mean standard deviation, 75.3 +/- 11.7 years) who were classified as stage 3 or had mobile segments of bony sequestrum, and intake of the offending drug was ceased. The sequestrum was removed with surrounding vital bone, and segmental resection was performed in one patient with a pathological mandibular fracture. The outcome was classified into one of the following three categories: "Healing," "Improvement," "Unchanged." and "Exacerbation." The mean postoperative follow-up period was 16.6 months (3.0-57.9 months), and complete healing was observed in 21 patients (80.8%), improvement of the lesion was observed in four patients (15.4%), and the outcome of one patient was unchanged (3.8%). The procedure described here may be recommended with relatively high clinical success rate for the patients with MRONJ requiring surgical treatment.