The purposes of our study were, first, to determine the prevalence of dental caries in young patients with congenital cardiac disease, second, to determine the effect of oral health in their quality of life, third, to examine parental knowledge about associations between oral health and cardiac health, and fourth, to examine parental perceptions regarding access to dental care. A standardized questionnaire was given to a convenience sample of parents of 43 children with cardiac disease and 43 healthy controls from 12 to 71 months of age. In every patient, we performed a dental examination. Descriptive statistics, the two-tailed t-test, and Fisher’s exact test were used for statistical analysis. Of the children with cardiac disease, 17% had caries, compared to 13% of the control group. Almost half of those with cardiac disease had never seen a dentist, compared to 35% of the control subjects. Of the parents of those with cardiac disease, one-fifth did not know whether oral health was important for the heart, compared to one-tenth of controls. Insurance and access to care were not barriers to obtain dental treatment. Statistically significant differences were, first, parents of children with congenitally malformed hearts felt more guilt about their child’s oral health than control parents (p = 0.026), second, they were more upset about the dental problems and/or treatments of their children (p = 0.012), and third, they thought that dental problems and/or dental treatment made their children more irritable (p = 0.012). Our findings indicate that it is of paramount importance that cardiologists and their associated staff educate patients and families about oral health and other issues associated with congenital cardiac disease.