An observational study was conducted in 164 patients with resistant or difficult-to-control hypertension. Treatment was adjusted to achieve blood pressure recommendations from the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7). Patients were mostly male (95.73%) and African American (86.59%) and had an average age of 63.68 years. Comorbidities included diabetes (42.07%) and chronic kidney disease, with an average estimated glomerular filtration rate of 83.55 mL/min/1.73 m(2). At the time of referral, average blood pressure was 160/87 mm Hg. The average number of antihypertensive medications per patient at baseline was 3.43, which increased to 4.06 and 4.18 at 3 and 6 months, respectively (P< or =.0008), with about 80% of patients receiving a diuretic prior to intervention. Blood pressure decreased to 135.55/74.55 and 137.62/74.03 mm Hg at 3 and 6 months, respectively (P<.0001). By month 6, the blood pressure goal was reached in 45.10% of patients. At months 3 and 6, 100% of patients were now receiving a diuretic. The average estimated glomerular filtration rate at month 6 was 79.36 mL/min/1.73 m(2) (P=NS). Patients referred for resistant or difficult-to-control hypertension may be controlled by making targeted adjustments to their medical regimen.