Cryptogenic organizing pneumonia (COP) is a pneumonic process that is pathologically characterized by plugs of granulation tissue in distal airspaces. It typically manifests with cough, dyspnea, fever, and multiple, often migratory, patchy pulmonary infiltrates. Corticosteroids are the standard therapy for COP, and a 6- to 12-month treatment course is resolutive in most cases. However, many patients experience multiple relapses and thus require more prolonged treatment, which may be complicated by severe and sometimes disabling side effects. In similar circumstances, certain macrolide antibiotics seem to be a promising alternate therapeutic option to corticosteroids due to their immunomodulatory properties. Azithromycin as an immunomodulatory agent has been used rarely in COP and only at the full dose (500 mg/d) and in association with steroids. A patient with migratory and multirelapsing COP had to stop corticosteroids due to serious side effects including avascular necrosis of the femoral head. This is the first case of COP that was treated successfully with azithromycin at low dose (250 mg/d) and as a single agent.