Hypertension is a common chronic illness that affects 50 million individuals in the United States and approximately 30% of adults worldwide. United States emergency departments report > 900,000 annual visits for hypertension-related complaints and studies show that approximately one-third of patients with elevated blood pressure lack a formal prior diagnosis. These patients are at risk for long-term morbidity and mortality from cardiovascular, ocular, and neurological consequences. This review examines the most current evidence regarding emergency department treatment of asymptomatic hypertension, including differentiating hypertensive emergency from poorly controlled hypertension, recommendations for choosing appropriate treatment, determining the need for admission, and guidelines for disposition and follow-up.