PURPOSE OF REVIEW A major advantage of transcranial Doppler (TCD) ultrasound is its ability to measure cerebral hemodynamics noninvasively at the patient's bedside. This article summarizes the basic physics and variables used during TCD, recent pediatric data published on the use of TCD in stroke and cerebrovascular disorders and how it may impact diagnosis and management, and some issues to be resolved so that TCD can be put into clinical practice. RECENT FINDINGS In sickle cell disease in children, TCD is the gold standard stroke prediction tool. Recent data suggest that TCD may provide important information in ischemic stroke because of other childhood arteriopathies such as moyamoya syndrome, transient or focal cerebral arteriopathy, and genetic/syndromic causes. TCD may also detect cerebral emboli and diagnose right-to-left atrial cardiac shunts in children with cryptogenic stroke and transient ischemic attack. SUMMARY There are many potential clinical applications for TCD in pediatric stroke and cerebrovascular disorders. Additional research in children is needed to determine whether TCD can identify markers of increased stroke risk, elucidate underlying stroke mechanisms, influence the choice of additional testing and treatment, and ultimately impact patient outcomes.