To identify factors associated with refractory severe hypertension that does not resolve after an initial dose of antihypertensive medication in patients with preeclampsia. This was a retrospective study of all pregnant and postpartum individuals with a diagnosis of preeclampsia, superimposed preeclampsia, HELLP (hemolysis, elevated liver enzymes, low platelet) syndrome, or eclampsia who delivered at 22 weeks or greater at a single academic institution from 2010 to 2020. Inclusion criteria were patients with preeclampsia who developed severe hypertension (systolic pressure 160 mmHg or more or diastolic pressure 110 mmHg or more) and received antihypertensive medications for acute severe hypertension. We defined refractory severe hypertension as a systolic blood pressure of 160 mmHg or greater or a diastolic blood pressure of 110 mmHg or greater that did not improve after receiving the initial treatment. To evaluate for factors associated with refractory severe hypertension, we developed multivariable modified Poisson regression using all variables with p-value < 0.1 on bivariable analysis and calculated adjusted relative risks (aRRs) with 95% confidence intervals (95%CI). Of 850, 386 (45.4%) had refractory severe hypertension and 464 (54.6%) responded to the initial antihypertensive medications. Factors associated with refractory severe hypertension included higher body mass index (BMI), chronic hypertension, and higher systolic pressure. Every 5 kg/m2 increase in BMI was associated with a 7% increased risk of refractory severe hypertension (aRR 1.07; 95%CI 1.02-1.12). Every 10 mmHg increase in systolic blood pressure was associated with a 10% increased risk of refractory severe hypertension (aRR 1.10; 95%CI 1.04-1.17). Chronic hypertension was associated with a 25% increased risk of refractory severe hypertension (aRR 1.25; 95%CI 1.01-1.56) in the diastolic pressure model. Refractory severe hypertension was associated with elevated BMI, chronic hypertension, and higher systolic blood pressure.