All renal allograft biopsies performed in Princess Margaret Hospital from 1st April 2002 to 31st March 2006 on Chinese patients who were ≥ 18 years old were retrospectively reviewed. Renal transplantations were either cadaveric or living-donor related performed in Hong Kong or Mainland China. All recipients' sera produced negative cross-match tests with donor lymphocytes before transplantation and were ABO compatible. Finally, 52 renal biopsies were included. 38 (73.1%) of them were performed for unexplained acute renal deterioration whilst the rest were done for delayed graft function.