Long-term treatment goals of bronchiectasis frequently include limiting the bacterial burden and inflammatory insult in the airways with the aim of improving symptoms, reducing exacerbation frequency and severity, and improving health-related quality-of-life. However, few clinical or laboratory markers specifically validated for bronchiectasis exist, and how best to assess the disease and its response to treatment is poorly understood. Pertinent, reliable markers are urgently needed to facilitate effective treatment of bronchiectasis and to ensure ongoing development of future therapies. This article explores the utility of potential end points in evaluating therapies used in the long-term management of stable bronchiectasis.