A case of trisomy 21 associated with nonimmunologic hydrops fetalis (NIHF) is presented. As Rh isoimmunization has markedly declined, nonimmunologic hydrops fetalis has become the most common type. Only 25 cases (trisomy 21, n-17; trisomy 18, n-6; trisomy 13, n-2) has been previously reported till 1986. The association between NIHT and chromosomal trisomies is stiIl remain unknown. Their features are often distorted by edema, this obscuring the phenotypic characteristics of the common trisomies. This case emphasize chromosomal abnormalities should always be considered in the differential diagnosis of NIHF in the fetus and neonate.