Russell-Silver syndrome is a genetic disorder characterized by intrauterine and/or postnatal growth restriction and typical facies. The clinical feature is various due to heterogeneous genetic characters. Their common findings are short stature without catch-up growth, normal head size for age, a distinctive triangular face with prominent forehead and a pointed chin, low set ears and clinodactyly of the fifth fingers. Intraoral features of the syndrome are microdontia, delayed tooth eruption, hypodontia, and crowding. More than 400 case have been reported in the literature, and estimated incidence is from 1 in 3000 to 1 in 100,000. In this case we performed caries treatment under the general anesthesia for the patient with Russell-Silver syndrome. Dentist have to consider microstomia for the management of patients with Russell-Silver syndrome