OBJECTIVES: To evaluate the knowledge of senior dental students and newly graduated dentists about the prevention, diagnosis and treatment of oral manifestations of syphilis. MATERIALS AND METHODS: A 32-question questionnaire was designed with three domains: (I) demographic, academic and professional data of the participants, (II) attitudes, practices and self-perception regarding training about syphilis and (III) knowledge about syphilis. All knowledge responses were classified as correct or incorrect. Scores ranging from 1 to 14 were calculated, and grades were assigned to each participant according to their level of knowledge. RESULTS: The sample comprised 408 dental students and 339 newly graduated dentists. The mean score was 7.70 ± 3.35 for undergraduates and 9.09 ± 3265 for dentists. The highest frequency of correct answers (>70%) was attributed to questions about the aetiology, transmission and treatment of syphilis. The questions with the lowest frequency of correct answers (<50%) were about the identification of oral manifestations and stages of syphilis. CONCLUSIONS: The knowledge of dental practitioners and academics about the oral manifestations of syphilis was unsatisfactory. The lack of understanding of these aspects can delay the diagnosis and treatment of patients with this disease, which is concerning given the steady increase in cases in recent years.