Congenital heart diseases (CHDs) are known to be related to structural and developmental disturbances of teeth, such as anodontia, microdontia, enamel hypoplasia, affected normal form of teeth. A recent research points out that enamel and dentin of primary teeth of children with CHD are structurally and chemically altered, with low calcium and phosphorus levels. Tooth decay and periodontal diseases have low morbidity rates, but they both have high prevalence and cause oral pain. They are risk factors for other systemic complications, most likely in children. Children with CHD are at higher risk of complications, because their main disease may worsen due to oral diseases. The main risk is life-threatening systemic conditions such as infectious endocarditis and brain abscess, caused by odontogenic bacteremia. The available information, concerning oral manifestations and specifics in the dental clinics and prophylaxis of children with CHD, is still scarce and insufficient despite the social significance of this problem.