Background. Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse drug reaction characterized by progressive bone destruction and necrosis of mandibular and/or maxillary jaw bone that occurs in patients undergoing treatments with antiresorptive drugs such as bisphosphonates or denosumab, antiangiogenic agents such as bevacizumab, or other kinds of monoclonal antibodies such as rituximab and ipilimumab, for different oncologic and nononcologic diseases. The aim of this study was to report a case of MRONJ in a patient affected by rheumatoid arthritis disease in treatment with adalimumab. Case Presentation. A 70-year-old female patient affected by rheumatoid arthritis (RA), who had been undergoing adalimumab (40 mg subcutaneous injection) every two weeks for 5 years, with no history of antiresorptive or antiangiogenic agent administration, came to our attention for intraoral necrotic bone exposures of the anterior mandible. After drug withdrawal and antibiotic cycles, the patient underwent surgical treatment with bone resection and debridement of necrotic tissues. After an observation period of 8 months, a complete healing without signs of recurrence was detected.Conclusions. Based on this study, a correlation between adalimumab and MRONJ is possible. Therefore, we believe that an oral cavity examination should be done in every patients, before starting therapy with adalimumab, to possibly avoid MRONJ onset. Further studies are required to confirm the role of adalimumab in MRONJ.