To evaluate the impact of oral health on the quality of life (QOL) of individuals undergoing cancer treatment at the time of diagnosis of medication-related osteonecrosis of the jaw (MRONJ). The present cross-sectional study analyzed patients with MRONJ from 2013 to 2019. The collected data included demographic data, base disease, medications associated with MRONJ, route of administration and time of use, signs, symptoms, and tomographic features of acute MRONJ, staging according to American Association of Oral and maxillofacial Surgeons position paper 2014 (AAOMS), type of dental treatment performed, outcome, and the responses to the Oral Health Impact Profile questionnaire (OHIP-14). Statistical analysis was performed using the Tukey test to study the association between oral condition and the QOL. A p-value of less than 0.05 was considered statistically significant. The sample consisted of 16 medical records of patients with MRONJ. Psychological discomfort showed alarmingly significant results (p< 0.001) with strong negative impact on the QOL of the patients. Functional limitation was the least affected dimension (p = 0.747). The other dimensions did not show statistically significant results. MRONJ compromises oral health and negatively impacts the QOL, especially with respect to the psychological discomfort (worry and stress). The OHIP-14 questionnaire proved to be an effective tool in the assessment of this impact.