Non immunologic hydrops fetalis (NIHF) is relatively more frequent now since prevention and treatment of blood incompatibilities are common. Seven cases of NIHF were observed between November 1984 and April 1987; antenatal diagnosis by ultrasound scanning was possible in six of these seven cases. Fetal prognosis is usually poor. Only one of the seven children survived, four infants died shortly after birth; two women chose an elective termination of pregnancy at 18 and 23 weeks of gestation, respectively. The review of the literature shows that more than 150 etiologies are associated with this condition. An etiology was found in five of our seven cases, these were all different; renal vein thrombosis, cardiac malformation, cystic hygroma, osteogenesis imperfecta and one case of recurrent NIHF (four affected siblings). Two cases remained idiopathic. Diagnosis of NIHF is best oriented by three investigations: obstetrical ultrasound scanning, fetal echocardiography and any kind of amniocentesis, either for karyotype alone, or to evacuate pleural, pericardial of peritoneal effusions. Ultrasound scanning can evaluate the importance of these effusions and help to choose other etiological investigations. Fetal echocardiography is mandatory because out of the 150 etiologies described in association with NIHF, 25% are cardiac (malformation or dysrhythmias). As already mentioned, fetal prognosis in our series was poor, but perhaps more aggressive in utero treatment could have improve it.