Chronic obstructive pulmonary disease (COPD) is a major public health problem, associated with considerable morbidity and health care costs. The global burden of COPD morbidity is predicted to rise substantially in the coming decade, but could be moderated by better use of existing management strategies. Smoking cessation, medication therapy, and pulmonary rehabilitation have all been shown to diminish morbidity and improve patient outcomes. But each of these strategies requires adherence. Adherence is crucial for optimizing clinical outcomes in COPD, with nonadherence resulting in a significant health and economic burden. Suboptimal medication adherence is common among COPD patients, due to a number of factors that involve the medication, the delivery device, the patient, and the health professionals caring for the patient. Lack of medication adherence needs to be identified and addressed by using simplified treatment regimens, increasing patient knowledge about self-management, and enhancing provider skills in patient education, communication, and adherence counseling. This article reports some of the challenges of medication nonadherence faced by the clinician in the management of COPD, and suggests ways to evaluate and improve adherence effectively in primary care.