Objectives: The aim of this study was to evaluate the profile of patients on antiresorptive therapies for cancer treatment and assess presence of oral lesions, oral hygiene status, and knowledge regarding medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods: This was an observational cross-sectional study that evaluated patients treated with antiresorptive medication at a single cancer hospital. Clinical data were collected and oral examination was performed to assess patient oral health. Results: From July 2017 to December 2018, 90 patients were assessed; 64 were female and 26 were male, and the mean age was 61 years. The most common drug was an intravenous bisphosphonate, zoledronic acid. Among the 90 patients, 47 presented with some type of oral disease, isolated or associated. Among these 47 patients, 9 patients (10%) developed osteonecrosis. Oral hygiene was evaluated, and most patients, with or without MRONJ, presented with regular to poor condition. Regarding patient knowledge of the risks of MRONJ and the risks associated with dental surgery, 60% stated that they were not aware of the risks. Conclusion Identifying the profile of patients and their needs facilitates not only the preventive process, but also the emergence of new therapeutic options. Our study shows that most patients are weakened both by metastatic disease and antineoplastic treatment as well as by issues associated with aging because most were over 60 years of age. Collectively, this information should be considered for management of preventive and therapeutic measures.