Fifteen infants with macrocephaly had a head growth pattern parallel to 2 SDs above normal. In eight patients with initial and subsequent normal findings on neurological and developmental examinations, computerized tomography (CT) showed slight ventricular dilation and increased width of the subarachnoid space anteriorly. The other seven patients had abnormal results from neurological or developmental examinations. The CT findings in two were similar to those in the first group; in four, other abnormalities were observed; and one had a normal scan. None of the 15 infants required shunting. In infants with this head growth pattern, a similar CT scan with ventricular dilation and widened subarachnoid space could be found in patients with normal or abnormal results from neurological and developmental examinations. Those infants with this CT scan pattern and normal neurological and developmental findings appear to have a benign condition.