Meckel-Gruber syndrome is a rare, OR-transitive and fatal disease. Prenatal diagnosis is important, especially in regions where consanguineous marriages are common. The classic triad of the disease is occipital meningoencephalocele, renal anomalies and postaxial polydactyly. The diagnosis is made by the presence of two of these three major features. Just over 200 cases have been reported in the world literature. The purpose of presenting our case is that all findings of the disease were detected in both fetuses in a twin pregnancy for the first time, which has not been reported in literature.