Meckel-Gruber syndrome (MGS) is a lethal, rare, autosomal recessive condition manifested by clinical and genetical heterogenicity. The syndrome is characterized by the triad: occipital meningo-encephalocele, cystic displastic kidneys and postaxial polidactyly. The diagnosis is suspected by ultrasound and in families at risk of reccurrence of the syndrome it is made in the late first trimester of pregnancy. We present a patient with a previous pregnancy terminated in the second trimester because of ultrasound features for MGS, in whom a correct transvaginal ultrasound diagnosis of the same syndrome was made in 13 w.g. of the present pregnancy.