This paper discusses 33 cases of Apert's syndrome which were treated in the Australian Craniofacial unit at the adelaide Children's Hospital. The main features were discussed. We found that mild ventricular dilatation is common in Apert's syndrome but without associated raised intracranial pressure. Severe ventricular dilatation was seen in only one case. No shunt procedures were performed. We also studied the changes in the ventricular size after transcranial corrective procedures. There was no significant change in the ventricular size, the increase in the skull volume was compensated by expansion of the brain tissue and to some extent by increase in the subarachnoid space. Two cases with unusual features are also described.