Poor control of hypertension is common, but its causes are not always easy to discern and thus are often not readily corrected. A well-known cause of poor blood pressure control is poor patient adherence to therapy. Reliance on short-acting antihypertensive drugs may contribute to both problems. According to various clinical trials, more even blood pressure control can be achieved with long-acting antihypertensive agents administered once daily. Given these agents' ease of dosing and persistence of effect, their use is likely to improve adherence and control. Physicians can also have a positive impact by providing patient education that stresses the importance of patients' long-term adherence to their prescribed drug regimen even in the absence of symptoms. Moreover, they can create an atmosphere in which patients feel free to voice their concerns about their disease, ask questions about their drug regimen, and discuss any adverse effects or recommended lifestyle changes that may be undermining their adherence to the therapy prescribed.