BACKGROUND: The Saudi Ministry of Health (MOH) has published detailed guidelines and educational documents about Coronavirus disease 2019 (COVID-19) prevention and infection control. The knowledge of dentists of the reported guidelines is not yet assessed and lack of awareness of these guidelines may have negative implications on dental patients. AIMS: The aim of this study is to assess the knowledge of dentists about COVID-19 and the MOH guidelines while treating dental patients in Saudi Arabia. MATERIALS AND METHOD: A cross-sectional study was conducted using an online survey which was sent to a sample of dentists in Saudi Arabia from March to May 2020. RESULTS: A total of 294 dentists with a mean age of (36.9 ± 10.6) years completed the questionnaire. Participants included 157 females and 137 males with a range of professional classification and experience. All of the participants were aware of COVID-19, the nature of the disease, symptoms, modes of transmission and people at higher risk, except for 7.2% who did not report the correct incubation period. All participants agreed that patients and staff should wear a facial mask, use hydroalcoholic hand sanitizer upon arrival. Only 72.4% had knowledge about published guidelines. Infection control training was provided for 53% of the participants and those who had training were more confident to treat patients. Regarding personal protective equipment (PPE), putting on and taking off PPE, 64.6% and 78.6%, respectively, were aware of the guidelines. CONCLUSION: Dentists in Saudi Arabia had optimal knowledge about COVID-19. However, infection control training is recommended to increase readiness and confidence among dentists.