A screening examination will be performed between 1 and 14 days before the start of the study (the day of first dosing with study drug). Patients who fulfill all of the inclusion and none of the exclusion criteria will be accepted on to the study. Patients who fail the renal or hematological function criteria may be re-screened if these parameters improve and if they are still being treated with Valcyte®. The following procedures will be performed to establish each patient's general health and eligibility for enrollment into the study: Record medical history, including etiology of end-stage organ disease, details of transplant (date and type), any previous disease (including CMV) and treatments, immunosuppressive drugs and doses within the previous month or from transplantation, whichever is the shorter, Record CMV serology of donor and recipient., perform physical examination; record demographic information including sex, age and race/ethnicity; Obtain vital signs, height and weight; Draw blood samples for laboratory screening of hematology (about one teaspoon of blood) and routine serum chemistry, including calculation of estimated creatinine clearance; Obtain a mid-stream urine sample for urinalysis and a pregnancy test (females only). This visit will take about 30 minutes. Patient will be seen while in hospital by the research coordinators and research physicians, while recovering from the kidney transplant procedure.