Objectives To assess the knowledge of dentists regarding medication-related osteonecrosis of the jaw (MRONJ). Methods In this cross-sectional study, 74 dentists from governmental hospitals in Riyadh (Dental University Hospital in King Saud University, Military Hospital, National Guard Hospital), Jeddah (King Abdulaziz University Hospital, Ministry of Health Hospital), and the Eastern region of Saudi Arabia (Ministry of Health Hospitals in Dammam and Al-Ahsa) completed a two-part questionnaire. The first part gathered demographic data, such as sex and specialty. The second part included questions about bisphosphonate drugs and their indications; the identification of patients at risk of MRONJ; other medications associated with jaw necrosis; as well as the definition of MRONJ and its clinical features, risk factors, and preventive methods. Results Of the participating dentists, 60.8% knew about MRONJ, but only 35.1% were able to define it correctly. Most (79.7%) had never encountered MRONJ patients. Only 18.9% knew of the relationship between the risk of MRONJ in osteoporotic patients and long-term (>4 years) use of oral bisphosphonates or intravenous zoledronate, while 68.9% were unaware, and others answered incorrectly. Most participants did not know of MRONJ-predisposing medications, and 59.5% cited radiotherapy as the cause. Most participants identified dentoalveolar surgery as a major local factor, and the mandible as a common anatomic location. Conclusion Dentists at the surveyed institutions had poor knowledge of MRONJ, although their knowledge of preventive measures was good. There is an urgent need for the optimization of educational programs pertaining to MRONJ, and its related dental management considerations. Clinical significance Dentists in the surveyed institutions in Kingdom of Saudi Arabia have poor knowledge of MRONJ management; thus, greater effort should be taken to educate undergraduate and postgraduate students regarding this pathology.