The authors report the results of prenatal diagnosis of the hypoplastic left heart syndrome since 1998 in the University Hospitals of Marseille and Montpellier. Twenty-four prenatal diagnoses of this condition were made in mothers with a mean age of 29 (18 to 40 years) and after a mean term of 22 (18.5 to 33) weeks of amenorrhea. Seventeen therapeutic abortions were carried out and 7 neonates born after a mean term of 39 (28 to 40) weeks, were admitted to the paediatric intensive care unit. Two patients required ventilatory assistance with one early death. The other patients were stable after surgery. A Norwood (first stage) procedure was carried out in 6 neonates at a mean age of 5 (1 to 6) days. There was only one survivor (17%). Prenatal diagnosis of the hypoplastic left heart syndrome allows cardiac and extracardiac evaluation of foetuses with this condition. Therapeutic abortions may be proposed and was the commonest choice of the parents in this study. On the other hand, despite better management of neonates with this prenatal diagnosis, the poor prognosis of the Norwood first stage procedure is unchanged. A systematic search for a restriction of the foramen ovale on foetal echocardiography could optimise neonatal management of this problem.