© Elsevier Inc. Acute dysfunction of a kidney transplant can be the result of many different etiologies and an allograft biopsy is frequently necessary to diagnose acute rejection. This invasive procedure, while generally safe, is time consuming, costly and inconvenient. We summarize recent advances in genomic and proteomic techniques using peripheral blood and urine for the diagnosis of acute rejection. While much progress has been made, validation of these new molecular tests in the clinical setting is still required.