Williams (Elfin Facies) syndrome is a rare, devastating, sporadic disorder first described in 1961. Approximately 100 cases have been reported in the literature. The disorder is characterized by multiple anomalies including mental deficiency, an unusual (elfin) facies, supravalvular aortic stenosis, prenatal and postnatal growth deficiency, infantile hypercalcemia, a small mandible, and frequent dental problems. Because of these anomalies, the dentist contributes significantly to the successful management of these patients. Infant dental care, nutrition counseling, and restorative care are extremely important for maximizing the quality of life for patients with Williams syndrome. A review of the literature and the successful management of a patient with Williams syndrome are presented.