Dental caries, commonly known as tooth decay, is an oral disease in which the acid generated by specific types of unfriendly bacteria cause damage to hard tooth structure. It is one of the most common infectious diseases among American children and adults, and remains one of the most common diseases throughout the world. Caries prevention attempts to reduce the odds of developing this disease. The dental health professional plays a crucial role in preventing caries by educating the patient about the causes of caries, and by offering information that promotes caries-reducing habits and, hopefully, puts an end to unhealthy habits. However, effecting behavior change in a patient is a complex process that requires continuous support. Understanding the many psychological, social, cultural, and economic barriers to change, how to communicate effectively, and how to help a patient set health-promoting goals are discussed as means to effecting change that can lead to caries prevention.