Sturge-Weber syndrome (SWS) is a neurocutaneous disorder that is typically associated with progressive neurological deterioration. We describe a 12-year-old girl with SWS who suffered a permanent cerebral insult as the result of a period of protracted status epilepticus. The case illustrates the unique susceptibility of patients with SWS to uncontrolled venous hypertension and emphasises the need for optimal seizure control and preservation of venous outflow. We discuss the relevance of our observations to haemodynamic concepts of neurological decline in SWS.