Transcranial duplex sonography (TCCD) is a non invasive imaging method for workup of intracranial vasculature, cerebral hemodynamic and brain parenchyma. TCCD can be used in different phase of stroke from screening in children with sickle cell disease for primary stroke prevention, acute stroke treatment until planning for secondary stroke prevention. For ischemic stroke, TCCD is usually utilized to assess degree of intracranial stenosis, collateral circulation, and recanalization of occluded artery after thrombolysis. Other clinical applications of TCCD are evaluation of vasospasm in subarachnoid hemorrhage, cerebral venous thrombosis, intracranial aneurysm, arteriovenous malformation, brain tumor, intracerebral hematoma, degenerative disease such as Parkinson disease, and brain death. The use of ultrasound contrast enhanced TCCD can examine cerebral perfusion to evaluate final infarct core and clinical prognosis, and also enhances the ultrasound signals in the patients with inadequate or no temporal bone windows. TCCD can apply in many patients without definite contraindication and easily for follow up as much as possible. However, TCCD is operator dependent and needs some skill in term of technical training and interpretation of results follow the standard diagnostic criteria to improve the accuracy of diagnosis.