The present invention relates to a composition comprising cyclosporine A (CsA) for use in the prevention of bronchiolitis obliterans syndrome (BOS) in a double lung transplanted patient, or for the treatment of BOS or for the prevention or delay of the progression of BOS in a double lung transplanted patient being diagnosed with BOS, wherein the composition is administered to said patient by inhalation of said composition in aerosolized form comprising a therapeutically effective dose of cyclo- sporine A.