The persistent pulmonary hypertension syndrome is a heavy and very often a lethal complication in the neonatal period. It is more common in full-term infants with perinatal asphyxia, meconium aspiration or inborn infection. We discuss two clinical cases of newborns, delivered by Caesarian section in the 38th week of gestation without history of prenatal asphyxia or inborn infection. The main clinical symptom was a progressive lung failure that finally lead to mechanical ventilation. Both infants had clinical symptoms of pulmonary hypertension and intracranial hemorrhages (proved by ultrasound). During autopsy, bilateral pneumonia and intracranial hemorrhages were found in both infants and in one of them meconium aspiration and suprarenal gland hemorrhages were proven. In conclusion we may say that the diagnosis of persistent pulmonary hypertension is often very difficult and the conventional methods of mechanical ventilation and medicament treatment cannot always prevent the infant's lethal outcome.