MicroRNAs (miRNAs) are noncoding RNA molecules of 21 to 24 nt that regulate the expression of target genes in a post-transcriptional manner. Evidence indicates that miRNAs play essential roles in embryogenesis, cell differentiation and pathogenesis of human diseases. Kidney transplantation to treat end-stage renal disease has evolved rapidly from the first successful transplantations to the current widespread use of grafts from both cadaveric and living donors. But acute rejection is still a strong risk factor for chronic rejection in recipients of renal grafts. To investigate possible mechanisms, we describe a comparison between miRNA expression profile of acute rejection and the controls. Through microarray analysis and quantitative real-time RT-PCR confirmation, we identified 20 miRNAs differently expressed in acute rejection after renal transplantation. Our data thus indicate that miRNAs were potentially involved in the pathogenesis of acute rejection, and miRNAs can help to diagnosis, treat and prevent acute rejection after renal transplantation.