Chronic obstructive pulmonary disease (COPD) is a chronic airflow limitation that is usually progressive and not fully reversible. Treatment of the condition aims to reduce symptoms, prevent exacerbations and delay the progression of the disease. Although medication has not been shown to modify the long-term decline of lung function, various medications are available to prevent and control patients' symptoms, improve health status and reduce the occurence of COPD exacerbations. Patient adherence to medication for COPD is poor compared with rates for medicines for other long-term conditions. Non-adherence to medication is a risk factor for mortality, morbidity, hospital admission and increased mortality. There are a variety of strategies health professionals can use to improve patient medical adherence.