Headache accounts for 1 – 3% of emergency department (ED) visits globally and is associated with elevated blood pressure (BP). It is unclear if anti-hypertensive therapy provides benefits. This retrospective study assessed effects of anti-hypertensive therapy in ED headache patients on rescue analgesic need, hospital admissions, and length of stay (LOS). 1385 patients were included. 366 received anti-hypertensive therapy. The anti-hypertensive therapy cohort was older (p < 0.001) with increased odds of admission (p < 0.001) and 2.385 hrs longer ED LOS (p < 0.001). No difference in rescue analgesia was found (p < 0.429). Anti-hypertensive therapy in hypertensive ED headache patients is associated with increased hospital admission and ED LOS, but no difference in rescue analgesia utilization.