Costello Syndrome (CS) is a rare congenital disease characterized by a wide range of cardiac, musculoskeletal, dermatological, developmental and dental abnormalities. Intraoral, enamel defects, delayed eruption and malocclusion, are the most common findings. We report the case of a three-year-old girl who was referred to the pediatric dentistry department of hospital la Rabta (Tunisia). It exhibited many of the dental manifestations of CS as well as general abnormalities. In our early treatment approach, the anterior teeth which presented enamel defect were restored with composite resin to adjust the incisor shape and improve esthetics and chewing function.