The evaluation of patients with resistant hypertension should be directed toward confirming true treatment resistance, identifying the causes contributing to treatment resistance (including secondary causes of hypertension), and documenting target-organ damage. Treatment of resistant hypertension is aimed at reversing lifestyle factors contributing to treatment resistance, accurately diagnosing and appropriately treating secondary causes of hypertension, and effectively using multidrug regimens. Lifestyle changes, pharmacologic therapies, and nonpharmacologic therapies have all shown benefits in patients with resistant hypertension, but much additional knowledge is needed to better identify and treat these patients.