Camptodactyly and pulmonary hypoplasia syndrome was described for the first time in 1974. Today 15 cases have been found. None were subject to a prenatal diagnosis as any ultrasonography. The case we observe is a 27 years old woman, third gestation, showing a polyhydramnios at 25 weeks of gestation. The ultrasonographic examination showed deformation with a rounded abdomen, a narrow thoracic frame slightly concave, no gastric picture and hands in constant flexion. After elimination of the V.A.T.E.R.' syndrome the camptodactyly's syndrome with pulmonary hypoplasia was proposed. Because of the lethal character of this syndrome, the abortion was realised. The photos of the fetus were the same as the ultrasonographic pictures during the prenatal diagnosis. The absence of intrinsic (paralysis) or extrinsic (compression) movements of the fetus is very important in the genesis of "deformations". The severity of the deformities depends on the importance of akinesia.