Acute cellular rejection( ACR) is one of the major complications of the acute phase after lung transplantation. In addition, ACR is considered to be a major cause of chronic lung allograft dysfunction (CLAD). Therefore, the diagnosis and treatment for ACR are major issues at transplantation facilities. Surveillance bronchoscopy( SB) is performed at many institutions as the golden standard for ACR diagnosis, and our hospital also implements long-term post-transplant monitoring of ACR as a preventive measure for CLAD. However, the suitability of SB may be questioned due to the risk of complications such as bleeding and pneumothorax. Here, we would like to report the results of SB in our department and discuss future diagnosis and treatment policy for ACR.