Resistance arteries may play a critical role in hypertension, and correcting their structural abnormalities may improve the clinical outcome of hypertensive patients. There have been several studies of the effects of antihypertensive treatment on the structure of resistance vessels in hypertension. These studies have yielded inconclusive results regarding the ability of individual drugs to induce regression of the changes occurring in blood vessels in hypertension, both in experimental models and in humans. This article reviews the results of studies of antihypertensive treatment on resistance vessel structure and function, and in particular those of a recent study in which the effects of treatment with the angiotensin-converting enzyme inhibitor cilazapril and the β-blocker atenolol on the structure and function of subcutaneous resistance arteries were evaluated in a double-blind randomized trial in patients with mild essential hypertension. In this study, patients were randomly assigned to receive either cilazapril or atenolol, and blood pressure was effectively controlled for I year. Treatment for 1 year with cilazapril resulted in a significant reduction in the media-to-lumen ratio of resistance arteries dissected from subcutaneous gluteal fat biopsy samples, although the ratio was still slightly but significantly larger than that of resistance arteries of normotensive controls. In arteries from patients treated with atenolol there was no significant change in media-to-lumen ratio with treatment. Contractile responses to several vasoconstrictors, particularly endothelin-1, which were blunted in hypertensive patients, were normalized in the cilazapril-treated patients, but were unchanged in those taking atenolol. These results suggest that in humans it is possible to correct in part the vascular remodeling present in hypertension. Treatment with drugs such as cilazapril and possibly other converting-enzyme inhibitors may provide better clinical outcomes in the treatment of hypertension by improving resistance vessel structure and function.