Tetralogy of Fallot (TOF) is the most common cause of cyanotic heart disease. The anatomic defects comprising TOF lead to the systemic circulation of oxygen-poor (desaturated) blood, resulting in symptoms of cyanosis, polycythemia, and hypoxia. Untreated, most patients with this disorder die during childhood. Surgical treatment aimed at correcting the defects is currently recommended for infants. Long-term studies have reported good results with this approach. The case history of a four-year-old male with uncorrected tetralogy of Fallot is presented. The patient required extensive dental treatment prior to scheduled cardiac catheterization. The dental findings and plan of care for this patient are detailed, and attention is given to the role of the medical work-up, preoperative antibiotics, and sedatives. It is stressed that the dental treatment plan for patients with tetralogy of Fallot must take into account the patients' medical status both prior to and following corrective surgical procedures.