Background/Aims: The Hyperlink trial tested a 12-month intervention combining home blood pressure (BP) telemonitoring with pharmacist case management in patients with uncontrolled hypertension. The intervention resulted in improved BP control compared to usual care at both 6 and 12 months (57% vs. 30%, P=0.001). The mean number of medication classes increased compared to usual care (0.63 vs. 0.22, P<0.001). We use process of care data recorded by the pharmacists and BP telemonitoring data to elucidate reasons for intervention success. Methods: Hyperlink randomized 450 patients with uncontrolled BP from 16 primary care clinics, and 228 intervention group patients were enrolled from clinics. They used a home blood pressure telemonitor to transmit BP readings to a study pharmacist. Following an in-person intake visit, pharmacists consulted with patients over the phone every 2-4 weeks during the first 6 months, and at 2 month intervals thereafter. They adjusted antihypertensive therapy using a specific treatment algorithm based on BP telemonitoring data. The home BP goal was <135/85 mm Hg (<125/75 for patients with diabetes or kidney disease.) Results: Mean BP at the research clinic enrollment visit was 148/85, and 143/85 at the pharmacist intake visit. At this visit, pharmacists changed the antihypertensive drug regimen for 10% of patients, while medication changes occurred for 33% at phone visit 1, 36% at phone visit 2, and 19% at phone visit 3. Thereafter, medication changes continued to decline. At the intake visit, pharmacists judged medication adherence to be high (>80%) in only about half of patients, but at subsequent phone visits in >90% of patients. The mean home BP recorded by the pharmacists for patients at the first phone visit was 136/80, and fell steadily to a mean of 126/74 at 3 months, and thereafter declined more slowly to 123/73 at 5 months, with little change thereafter. Conclusions: Improved adherence and appropriate adjustments to the antihypertensive treatment regimen based on home BP telemonitoring resulted in rapid lowering of BP over a 3-month period. Our results imply that intensive intervention may only be needed for about 3 months in many patients with uncontrolled hypertension.