After a lung transplant recipient is put on the waiting list for subsequent lung transplantation, informed consent will be sought for the current study. If signed informed is obtained, the patient will be enrolled upon admission for transplantation at which moment he/she will be randomised to placebo or azithromycin according to a blinded randomisation-list. In accordance with his/her attributed study-number, each included patient will be assigned to a pre-numbered bottle containing the study-drug, which was pre-filled and blinded for its content and are delivered in advance to the ward by the University Leuven Hospital Pharmacy. From this bottle, a first loading dose of placebo (25 mL po syrup) or azithromycin (25 mL po syrup = 1000 mg) will be given by the nurse during preparation for subsequent lung transplantation (Day 0). After lung transplantation, 'add on' treatment of placebo (6.25 mL) or azithromycin (6.25 mL = 250 mg) syrup will be given via (naso)gastric tube or per os every other day (days 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29 and 31) by the nurses taking care of the patient in the early post-transplant period. In case of any serious suspected drug-interactions (however very unlikely) or adverse attributable to the study drug, the study will be promptly stopped in this patient. Serious adverse events will be monitored by the treating lung transplant physicians (blinded for the study-drug) and are defined as allergic reactions including skin reactions (rash, urticaria or Stevens-Johnson syndrome), angioneurotic edema and anaphylaxis, cardiac arrhythmias (ventricular tachycardia or torsades de pointes), neurologic disorders (convulsions). Routine immunosuppressive, prophylactic and necessary antimicrobial treatment according to standardized protocol is given to all patients, independent of study drug. After transplantation, routine follow-up (e.g. biochemical and microbiological blood analyses, chest radiography, pulmonary function testing and bronchoscopic evaluation with broncho-alveolar lavage and/or trans- or endobronchial biopsies will be performed as they are currently routinely being performed as part of the standard, prospective follow-up after lung transplantation.