The purpose of this symposium was to evaluate the reproducibility of a histological diagnosis in renal allograft nephropathy according to the Banff classification. Seven transplant nephrologists and pathologists independently diagnosed the same glass slide specimens from 10 cases (five cases of acute rejection and five cases of chronic allograft nephropathy). Their diagnoses were collated and analyzed for the reproducibility of histological diagnosis. Consequently, several issues that hinder diagnostic reproducibility were identified.