The association between admission blood pressure (BP) and outcomes in patients with transient ischemic attack (TIA) is not well defined. Patients in the United States national Get With The Guidelines-Stroke registry with a TIA were included. Admission systolic and diastolic BP was used to compute mean arterial pressure and pulse pressure (PP). A subset of this cohort was linked to Centers for Medicare and Medicaid claims data for postdischarge outcomes. The in-hospital outcomes of interest were: mortality, not discharged home, and inability to ambulate independently at discharge. Postdischarge, 30-day and 90-day outcomes of interest were mortality, readmission for stroke, and readmission for major cardiovascular event-composite of death, cerebrovascular, or cardiovascular readmission. Among the 218,803 patients with TIA, lower admission systolic blood pressure (SBP) was associated with worse in-hospital outcomes. Compared with patients with SBP of 150 mm Hg, a lower SBP of 120 mm Hg was associated with higher risk of in-hospital death (adjusted OR = 1.79; 95% CI = 1.50 to 2.12), not being discharged home (adjusted OR = 1.31; 95% CI = 1.27 to 1.36), or inability to ambulate independently at discharge (adjusted OR = 1.27; 95% CI = 1.23 to 1.31). Similarly, among the 64,352 patients in the Centers for Medicare and Medicaid-linked cohort, an inverse association between systolic BP and postdischarge mortality (p <0.0001), and major cardiovascular event (p = 0.0001) was observed at 30-days and at 90-days postdischarge. However, there was no relation between SBP and readmission for stroke either at 30-days (p = 0.35) or at 90-days (p = 0.11). Results were largely similar for diastolic BP, mean arterial pressure, PP, and outcomes. In conclusion, in patients with a transient ischemic attack, a BP paradox was observed, with higher admission BP associated with improved in-hospital, 30-day, and 90-day postdischarge outcomes.