Asthma and chronic obstructive pulmonary disease (COPD) are the 2 most prevalent chronic airway diseases. Much of the morbidity, mortality and health care costs of the diseases are associated with acute exacerbations, which are episodes of increased symptoms and airflow obstruction. Over the last decade evidence has emerged implicating virus respiratory tract infections as a major cause of exacerbations of both asthma and COPD. Current therapies are not very effective in the prevention or treatment of virus-induced exacerbations and exacerbations are therefore a major unmet medical need. The development of new and novel treatments requires a better understanding of the molecular and cellular mechanisms linking virus infection with exacerbations of asthma and COPD. This article provides an overview of current knowledge regarding the mechanisms of virus-induced exacerbations in both asthma and COPD. It will also review existing treatments and future treatments that are in advanced stages of development.