This chapter presents a commentary on the lung-specific complications following transplantation and this should be used to drive the investigation plan and management. Shared care protocols with effective communication should be organized in patients who live at a distance from the transplant center to ensure that local follow-up includes monitoring of the lung function and imaging. Acute rejection can be identified on lung biopsies obtained via transbronchial biopsy (TBBx) at fiberoptic bronchoscopy. Many transplant centers perform regular bronchoscopy and TBBx in addition to spirometry in the first year to enable early diagnosis and treatment of asymptomatic rejection, with the aim of preserving graft function and protecting against bronchiolitis obliterans syndrome (BOS). Recently the importance of detecting early, subclinical BOS before irreversible fibroproliferative disease has become established has been recognized, and a new stage of BOS 0-p has been added.