This chapter reviews the current state of conventional digital subtraction angiography (DSA) in contemporary neurovascular imaging practice, including indications, techniques, complications and comparison with noninvasive techniques. The main indication for carotid DSA in current practice remains the evaluation of carotid atherosclerotic disease and accurate measurement of stenosis. Complications related to DSA can be classified as puncture-site-related, contrast-medium-related or neurological. More problematic complications such as pseudoaneurysms or large hematomas requiring surgical intervention are more infrequent. Several mechanisms have been postulated to account for the occurrence of neurological complications. Several established measurement methods are used to quantify the severity of internal carotid artery (ICA) stenosis prior to revascularization. The North American symptomatic carotid endarterectomy trial (NASCET) method is most widely used in North America, while the European carotid surgery trial (ECST) method tends to be frequently used in Europe.