Previous studies have demonstrated the cost-effectiveness of physician–pharmacist collaborations to improve hypertension control. However, most studies have limited generalizability, lacking minority and low-income populations. The Collaboration Among Pharmacist and Physicians to Improve Blood Pressure Now (CAPTION) trial randomized 625 patients from 32 medical offices in 15 states. Each office had an existing clinical pharmacist on staff. Pharmacists in intervention offices communicated with patients and made recommendations to physicians about changes in therapy. Demographic information, blood pressure (BP), medications, and physician visits were recorded. In addition, pharmacists tracked time spent with each patient. Costs were assigned to medications and pharmacist and physician time. Cost-effectiveness ratios were calculated based on changes in BP measurements and hypertension control rates. Thirty-eight percent of patients were black, 14% were Hispanic, and 49% had annual income <$25 000. At 9 months, average systolic BP was 6.1 mm Hg lower (±3.5), diastolic was 2.9 mm Hg lower (±1.9), and the percentage of patients with controlled hypertension was 43% in the intervention group and 34% in the control group. Total costs for the intervention group were $1462.87 (±132.51) and $1259.94 (±183.30) for the control group, a difference of $202.93. The cost to lower BP by 1 mm Hg was $33.27 for systolic BP and $69.98 for diastolic BP. The cost to increase the rate of hypertension control by 1 percentage point in the study population was $22.55. Our results highlight the cost-effectiveness of a clinical pharmacy intervention for hypertension control in primary care settings.