Lung transplantation is often the only treatment option that can prolong overall survival for patients with end-stage pulmonary disease. The number of lung transplantation procedures is increasing. However, overall survival of lung transplanted patients still lags behind that of patients after other solid organ transplantations. Death in these patients is mostly attributed to graft failure, chronic allograft dysfunction, infection, malignancy, and cardiovascular complications. Allograft rejection can result in graft failure and has also been associated with chronic allograft dysfunction. Transbronchial allograft biopsy is currently the gold standard for the assessment of rejection. However, sometimes, it can be challenging to distinguish rejection from its morphologic mimickers. Therefore, this chapter describes not only morphologic features of rejection but also differential considerations including infections that are important as they require alterations in management and treatment. Other lung transplantation pathology-related aspects such as explant pathology, perioperative complications, neoplasms, recurrent disease, and donor-derived findings among others will also be discussed.