Some macrolides have been found to exert anti-inflammatory effects. Lung diseases such as asthma, panbronchiolitis, cystic fibrosis, and bronchiectasis are thought to respond to the immunomodulatory properties of macrolides. We report three cases of idiopathic bronchiolitis obliterans organizing pneumonia, now called cryptogenic organizing pneumonia, and three cases of radiation-related bronchiolitis obliterans organizing pneumonia that responded to macrolide therapy. An explanation of why macrolides may have anti-inflammatory effects in patients with these syndromes is discussed. These cases help to reinforce accumulating data that macrolides are beneficial as anti-inflammatory agents and organizing pneumonia may be another pulmonary disease that can benefit from such therapy.