Despite improvements in the management of hypertension in the past several years, nearly 70% of patients with hypertension are not adequately controlled. Today's physician treating hypertension is armed with numerous efficacious antihypertensive agents. Thus, one of the major contributors to the large number of uncontrolled hypertensive patients appears to be non-compliance with prescribed regimens. Non-compliance is a universal characteristic and can affect all patients. However, the major problem of non-compliance is that it remains largely unrecognised in clinical practice. Several types of non-compliance exist with the 'drug holiday' being the most common. Good communication with the patient and the entire health care team is critical in increasing patient compliance. Long-acting medications that provide good blood pressure control beyond the 24-hour dosing period should be considered drugs of choice in non-compliant hypertensive patients. This article will discuss different types of compliance, methods to measure compliance, and clinical consequences of non-compliance in hypertension.