Sonographic pictures of the brain of 19 newborn infants who died at a mean age of 4.2 days after birth (range 1-23 days) were examined independently by five experienced sonographers. In all infants information on postmortem brain pathology was available. Diagnoses made by the sonographers based on the sonographic pictures were compared with the gross postmortem findings. The results of the study show that except for one infant with a subarachnoid hemorrhage all cerebral hemorrhages were diagnosed accurately by all sonographers. Non-hemorrhagic periventricular leucomalacia (PVL), however, was missed on sonography in 2 of the 3 cases. Surprisingly, PVL was diagnosed on sonography in 1 (8%) to 6 (50%) of 12 infants in which postmortem examination of the brain revealed no PVL. It is concluded that non-hemorrhagic PVL cannot be diagnosed accurately using sonography in the first days of life, if a 5 MHz transducer is used.