Background and Objectives: Severely elevated blood pressure (BP) in the emergency department (ED) has recently been associated with undiagnosed hypertension and adverse cardiovascular outcomes, regardless of the initial reason (e.g.: pain or anxiety) for the ED visit. Clinical uncertainty exists on how best to manage severe asymptomatic BP post-discharge from the ED. In this study protocol, we propose home BP telemonitoring with pharmacist case management intervention on participants discharged from the ED with severe asymptotic hypertension. The overall purpose of this trial is to evaluate whether home BP telemonitoring and pharmacist case management can improve BP management in participants discharged from the ED with severe asymptotic hypertension and whether participants find this intervention to be acceptable. Methods: The study is a multi-centre, randomized controlled trial of 408 participants discharged from the ED with severe hypertension (defined as average of 3 readings systolic blood pressure [SBP] ≥ 160 mm Hg and/or diastolic blood pressure [DBP] ≥ 100 mm Hg over 3 readings). Participants will be randomized to either usual care or home BP telemonitoring and pharmacist case management for 12-months. The primary outcome is proportion achieving disease specific SBP control using 24 h ambulatory BP monitoring (ABPM) at 12-months. Secondary outcomes are change in SBP and DBP based on 24 h ABPM and home BP averages at 6- and 12-months. Patient acceptability and satisfaction will be assessed using EuroQoL 5-level EQ5 version and patient Satisfaction Questionnaire Short Form. Exploratory outcomes include adverse events, prescription of anti-hypertensive medications, fidelity of interventions and health care utilization. Conclusions: Results from this study will advise the integration of home blood pressure telemonitoring and pharmacist case management pathway as key clinical strategy to improve patient flow in the ED, reduce length of stay in the ED, and improve BP control in patients with asymptomatic severe hypertension in the ED. Trial registration: ClinicalTrials.gov: NCT 06303206