Intravenous thrombolysis with recombinant tissue plasminogen activator is the standard of care for the treatment of acute ischemic stroke within 3 hours after stroke onset. Randomized clinical studies have demonstrated that intravenous thrombolysis improves functional outcomes but is not lifesaving. Complications of intravenous thrombolysis include severe intracranial hemorrhage that may be lethal. As with any therapy, consent cannot be assumed in the decision to use intravenous thrombolysis. Currently, there is no standardized method to estimate the capacity of patients with acute stroke, and empirical data for this patient population are limited. It is our position that candidates for intravenous thrombolysis should be properly assessed for their capacity to give direct consent before another form of consent is sought. We believe this would best be achieved by the development and standardization of a procedure for capacity assessment specifically for use in patients with acute stroke. To this end, we review the elements of informed consent, the legal standards for competence that a candidate for intravenous thrombolysis must meet to consent to treatment, recommendations for assessing capacity to give direct informed consent with attention to difficulties presented by the acute stroke setting, alternatives to direct consent with their inherent moral difficulties, and potential directions for research and discourse on capacity assessment in acute stroke.