Isoimmunisation RhD has an important perinatal morbidity and mortality. Since prophylaxis was introduced in the sixties, the incidence of haemolytic disease of the newborn has decreased. When administred in due time and in the right dosage anti-D immunoglobulin can prevent sensibilization. Nevertheless new cases continue to occur, underlying the need for an urgent improvement of our conduct. The purpose of this review is to provide an overview of the pathology of RhD isoimmunization and of aspects involved in its prophylaxis.