Hypertensive emergency is a clinical entity with potentially serious health implications and high healthcare utilization. There is a lack of nationally representative data on incidence, causes, and predictors of 30-day readmission after hospitalization for hypertensive emergency. We used the 2013 to 2014 Nationwide Readmissions Database to identify index hospitalizations for hypertensive emergency. Primary outcome was all-cause unplanned 30-day readmission. Multivariable hierarchical logistic regression was used to identify independent predictors of readmission. There were 166 531 index hospitalizations for hypertensive emergency representative of 355 627 (SE, 9401) hospitalizations nationwide in 2013 to 2014. Mean age was 66.0 (SE, 0.14) years, and 53.7% were women. The overall incidence of unplanned 30-day readmissions was 17.8%. The most common causes of readmission were heart failure (14.2%), hypertension with complications (10.2%), sepsis (5.9%), acute kidney injury (5.1%), and cerebrovascular accident (5.1%). Noncardiovascular causes accounted for 57.9% of readmissions. We found age <65 years (odds ratio, 1.21; 95% CI, 1.17-1.25; P<0.001), female sex (odds ratio, 1.09; 95% CI, 1.07-1.12; P<0.001), comorbid disease burden, substance use disorders, and socioeconomic risk factors to be significant predictors of readmission. One out of 6 patients hospitalized for hypertensive emergency had an unplanned 30-day readmission. Heart failure, uncontrolled hypertension, and stroke were among the most frequent causes of readmission; however, over half of all readmissions were because of noncardiovascular causes.