Aim: To assess the oral health practices and knowledge of practicing dentists at a tertiary health institution in Nigeria, and the possible association of age and sex with caries prevention practices. Methodology: A cross-sectional study was conducted. All practicing dentists in the institution were eligible to participate in the study. A questionnaire that assessed oral health practices and knowledge was administered. Respondents were expected to select the most appropriate responses that reflected their knowledge of oral health practices and caries prevention practices. Questions included assessment of knowledge and practice of tooth brushing, flossing, refined carbohydrate intake, and dental service utilization. Participantsâ€™ responses were scored and dichotomized to poor and good knowledge, and poor and good practices, using the median scores. Bivariate analysis was conducted to identify factors associated with good and poor oral health practices, and good and poor knowledge. Results: Fifty-two eligible study participants were accessible at the time of questionnaire administration. Only 46 respondents returned the filled questionnaire giving a response rate of 88.5%. The age of respondents ranged between 25 and 48 years. The majority of respondents had good oral health practices (65.2%) and good oral health knowledge (85%). However, few respondents had good caries prevention practices: 39.2% brushed at least twice daily, 45.7% took refined carbohydrate less than once daily, 36.9% used dental floss at least once daily, and 60.9% undertook preventive dental care. The correlation between the dentistsâ€™ oral health knowledge score and oral health practices score was insignificant (0.90; P = 0.55). Conclusion: A large number of dentists practicing in the tertiary hospital had good oral health practices and good oral health knowledge. However, the proportion of dentists with good caries prevention practices was low.