Over the last decade, improvements in surgical techniques, lung preservation, immunosuppression, and management of ischemia-reperfusion injury and infections have contributed to increase the 1 year patient survival after lung transplantation to 70 to 80%. However, the incidence of acute rejection remains higher than after other types of solid organ transplantation, and long-term survival is threatened by bronchiolitis obliterans, which is thought to be a form of chronic allograft rejection. This article reviews major aspects of clinical presentation, risk factors, diagnosis, and management of acute and chronic rejection after lung transplantation.