BACKGROUND: Hypertensive crisis is a life-threatening condition, further classified as hypertensive emergency and hypertensive urgency based on the presence or absence of acute or progressive end-organ damage, respectively. Readmissions in hypertensive emergency have been studied before. We aimed to analyze 30-day readmissions using recent data and more specific ICD-10-CM coding in patients with hypertensive crisis. METHODS: In a retrospective study using the National Readmission Database 2018, we collected data on 129,239 patients admitted with the principal diagnosis of hypertensive crisis. The primary outcome was the all-cause 30-day readmission rate. Secondary outcomes were common causes of readmission, in-hospital mortality, resource utilization, and independent predictors of readmission. We also compared outcomes between patients with hypertensive urgency and hypertensive emergency. RESULTS: Among 128,942 patients discharged alive, 13,768 (10.68%) were readmitted within 30 days; the most common cause of readmission was hypertensive crisis (19%). In-hospital mortality for readmissions (1.5%) was higher than for index admissions (0.2%, P<0.01). Mean length of stay for readmissions was 4.5 days. Mean hospital costs associated with readmissions were $10,950, and total hospital costs were $151 million. Age <65 years and female sex were independent predictors of higher readmission rates. Subgroup analysis revealed a higher readmission rate for hypertensive emergency than hypertensive urgency (11.7% vs. 10%, P<0.01). CONCLUSIONS: All-cause 30-day readmission rates are high in patients admitted with hypertensive crisis, especially patients with hypertensive emergency. Higher in-hospital mortality and resource utilization are associated with readmission in these patients.