A bimaxillary edentulous male patient, aged 67 years, diagnosed with prostate cancer who underwent intravenous bisphosphonates treatment (zoledronic acid) for about one year presented with pain in the anterior mandibular arch, with exposed necrotic bone, and was diagnosed with stage 2 medication-related osteonecrosis of the jaw (MRONJ). MRONJ is the development of bone necrosis in the oral cavity as an adverse reaction in patients treated with antiresorptive and antiangiogenic medication, without radiation therapy to the head and neck. This persistent bone necrosis does not always respond to standard treatments. The reconstruction technique with pectoralis major flap, at a distance, associated with the primary reconstruction plate, was an effective treatment modality for the treatment of large osteonecrosis noncompliant with conservatory treatments. Through this technique, the morpho-functionality of the jaw can be restored almost completely.