Long-term mortality in patients with acute severe hypertension is unclear. The authors aimed to compare short-term (hospital) and long-term (12 months) mortality in these patients. A total of 670 adults presenting for acute severe hypertension between January 1, 2015, and December 31, 2015, were included. A total of 57.5% were hypertensive emergencies and 66.1% were hospitalized: 98% and 23.2% of those with hypertensive emergencies and urgencies, respectively (P = .001). Hospital mortality was 7.9% and was significantly higher for hypertensive emergencies (12.5% vs 1.8%, P = .001). At 12 months, 106 patients died (29.4%), mainly from hypertensive emergencies (38.9% vs 8.9%, P = .001). Median survival was 14 days for neurovascular emergencies and 50 days for cardiovascular emergencies. Patients with hypertensive emergencies or urgencies had bad long-term prognosis. Short-term mortality is mainly caused by neurovascular emergencies, but cardiovascular emergencies are severe, with high mortality at 12 months. These results justify better follow-up and treatment for these patients.