Objective: This study assessed Nigerian dentists’ knowledge of current guidelines for the prevention of infective endocarditis. Material and methods: A self-administered questionnaire surveyed a cross-section of Nigerian dentists gathering information on respondent demographics, awareness of the American Heart Association current guidelines on preventing infective endocarditis and sources of knowledge regarding that guidance. Respondents indicated: a) whether or not they would prescribe antibiotics before dental treatment in 10 cardiac conditions, b) if antibiotic prophylaxis was reasonable before 10 dental procedures in an endocarditis high-risk patient, and c) a prescription for oral antibiotics for an endocarditis high-risk non-allergic adult about to undergo a dental procedure. Results: Respondents numbered 173 and 41% were aware of the guidelines. Most commonly the sources of this knowledge were undergraduate/postgraduate education. Overall, the correct responses for the 10 cardiac conditions was very low (33%), ranging from 94% for prosthetic heart valves (94.2%) down to 4% for previous coronary artery bypass (3.5%). For clearly invasive procedures, 80% to 96% of respondents indicated that a prophylactic antibiotic was reasonable. For clearly non-invasive procedures, 89% to 92% indicated that antibiotics were not reasonable. Correct antimicrobial agent, dose and timing of administration were prescribed by 89%, 9%, and 57% respectively. Conclusions: A low level of knowledge of the current guidelines was found among Nigerian dentists. Although, most prescribed the correct antimicrobial agent, the numbers prescribing correct dose and time of administration were quite low. Therefore, attempts should be made to teach the current guidelines in Nigerian undergraduate/postgraduate dental education. Key words: Nigeria, infective endocarditis