Asthma and chronic obstructive pulmonary diseases (COPD) are the most common obstructive lung diseases and may coexist in adults. The term ‘asthma and COPD overlap syndrome’ has been used to describe patients who have clinical features of both conditions. Recognition of the overlap syndrome is key to managing these patients successfully. The goals of treatment include reducing exposure to risk factors, reducing symptoms, maintaining lung function and normal activity, preventing exacerbations, reducing mortality and minimising adverse effects of treatment. Based on our understanding of the two disease processes, the cornerstones of pharmacological treatment in the overlap syndrome include anti-inflammatory agents and long-acting bronchodilators with rescue short-acting bronchodilators as needed. Smoking cessation is necessary for smokers, and pulmonary rehabilitation must be considered regardless of the predominant phenotype.