BK virus associated nephropathy (BKVAN) has emerged as an important cause of renal allograft dysfunction and graft loss. Although several treatment strategies have been proposed, the rate of graft loss remains high. We studied the outcome of renal transplant patients with BKVAN treated with IVIG. After 11.4 +/- 3.9 months (mean +/- SEM) from the time of transplantation, 8 renal allograft recipients were diagnosed with BKVAN. In addition to a reduction of immunosuppressive therapy, patients received 2 g/kg IVIG. After a mean follow-up of 15 months, all except one patient are,currently off dialysis. In summary, after IVIG therapy, 88% of patients still have functioning grafts, although renal function continues to be impaired. The benefit of concomitant IVIG and reduction of immunosuppressive therapy in BKVAN needs to be further addressed in randomized, multicentered trials.