Hypertension is an important cardiovascular risk factor and although there have been many improvements in pharmacological treatment, a significant percentage of patients are still considered resistant. The authors describe two cases of radiofrequency renal sympathetic denervation that illustrate the feasibility of this new technique for the treatment of resistant hypertension. The procedure consists of the application of radiofrequency energy inside the renal arteries to ablate afferent and efferent sympathetic renal activity, which has been implicated in the pathophysiology of hypertension.