Background. Dental caries and poor oral hygiene can affect the quality of life (QoL) of patients with congenital heart disease (CHD). Information about the oral health-related quality of life (OHRQoL) of Turkish preschool children with CHD is scarce. Objectives. The aim of the present study was to assess the OHRQoL, and the presence of caries, plaque and gingivitis in Turkish preschool children with CHD as compared to children without CHD (control group). Material and methods. Children aged 3–6 years with CHD (n = 75) and a control group (n = 75) were included in the study. Examinations were conducted using the plaque index (PI), the gingival index (GI) and the World Health Organization (WHO) caries diagnostic criteria. The Early Childhood Oral Health Impact Scale (ECOHIS) questionnaire was completed by the children’s families. Results. The amount of caries and plaque, as well as the number of missing teeth were higher in children with CHD. The OHRQoL was lower in children with CHD. However, the differences between the 2 groups were not statistically significant (p > 0.05). The number of filled teeth was significantly higher in the control group (p < 0.05). Conclusions. According to the findings of the present study, the high amount of caries and plaque in both groups demonstrates that caries continues to be a major public health problem. Although there was no significant difference in terms of QoL scale scores between the 2 groups, the study showed that OHRQoL was lower in children with CHD.