Prevention has been recognized as a cost-effective method for the control of oral diseases. Knowledge of prevention can influence preventive dental behavior. This study surveyed knowledge on the prevention of dental caries and gum disease among a selected group of adults. Respondents were asked to indicate the importance of numerous preventive measures for prevention of both categories of oral diseases. Results showed that while respondents appropriately identified the importance of regular brushing for prevention, the role of flossing is underestimated. Similarly, there was a lack of appreciation for the value of various fluoride treatment modalities in preventing dental caries. A lack of understanding of dental sealants was also evident. It is concluded that public knowledge on prevention of dental caries and gum disease deviates greatly from current scientific information.