Abstract: We describe a rare and devastating complication of a malpositioned scalp peripheral intravenous catheter (PIV) that resulted in subdural extravasation of infused fluids and midline shift in a critically ill neonate who required extracorporeal membrane oxygenation (ECMO). Recognition of increased intracranial pressure was hindered by the hemodynamic changes of being on ECMO and only identified by routine surveillance ultrasonography. Awareness of this complication may lead providers to seek alternate sites for vascular access in such patients, and encourage closer monitoring for this complication when an alternate site is unavailable.