Introduction: Decreases in blood pressure (BP) during thrombectomy are associated with infarct progression and worse outcomes. Many patients present first to a primary stroke center (PSC) and are later transferred to a comprehensive stroke center (CSC) to undergo thrombectomy. During this period, important BP variations might occur. We evaluated the association of BP reductions with neurological worsening and functional outcomes. Methods: We prospectively collected hemodynamic, clinical, and radiographic data on consecutive patients with LVO ischemic stroke who were transferred from a PSC for possible thrombectomy between 2018 and 2020. We assessed systolic BP (SBP) and mean arterial pressure (MAP) at five time points: earliest recorded, average pre-PSC, PSC admission, average PSC, and CSC admission. We measured neurologic worsening as a change in NIHSS (ΔNIHSS) from PSC to CSC >3 and functional outcome using the modified Rankin Scale (mRS) at discharge and 90 days. Relationships between variables of interest were evaluated using linear regression. Results: Of 91 patients (mean age 70±16 years, mean NIHSS 12) included, 13 (14%) experienced early neurologic deterioration (ΔNIHSS>3), and 34 (37%) achieved a good outcome at discharge (mRS<3). We found that patients with good outcome had significantly lower SBP at all five assessed time points compared to patients with poor outcome (Figure 1, p<0.05). Percent change in MAP from initial presentation to CSC arrival was independently associated with ΔNIHSS after adjusting for age, sex, and transfer time (p=0.03, β=0.27). Conclusions: Patients with poor outcomes have higher BP throughout the pre-CSC period, possibly reflecting an augmented hypertensive response. Reductions in SBP and MAP before arrival at the CSC are associated with neurologic worsening. These results suggest that BP management strategies in the pre-CSC period to avoid large reductions in BP may improve outcomes in patients affected by LVO stroke.