In addition to direct antibacterial actions, 14- and 15-member-ring macrolides have immune modulating effects that appear to be the reason for clinical benefit in diffuse panbronchiolitis. A literature search was conducted for studies of the clinical effectiveness of macrolides in other chronic lung conditions. A number of studies were identified that showed short-term beneficial outcomes or the potential for such outcomes in cystic fibrosis, bronchiectasis, chronic obstructive pulmonary disease, asthma and post-transplant obliterative bronchiolitis. The studies were limited by small patient numbers, different outcome measures and short-term follow-up, and were not designed to assess potentially harmful effects. Further large prospective and long-term studies are required in order to identify potential benefit and harm before these agents can be recommended routinely for these conditions.