Background: BK virus is one of the most infection cause of kidney graft damage and irreversible loss of graft function. There is currently no specific treatment regimen for BK virus, it is necessary to detect the activity of BK virus in patients early, especially in the early stages after transplantation. The study aimed to evaluate the diagnostic characteristics and treatment of BK virus infection in kidney transplant patients at the Organ Transplant Center, Viet Duc University Hospital. Methods: Patients who received a kidney transplant and were followed up at the Organ Transplant Center, Viet Duc University Hospital from January 2015 to September 2021. Results: The rate of blood BK infection ranges from 2.0 - 12.7%. Highest in the 3rd and 6th months. This rate gradually decreases after 12 months. The rate of urinary BK infection ranges from 13.3 - 35.3%. Most cases responded to immunosuppressant dose reduction, accounting for 85/106 patients (80.2%). There were 4 cases (3.77%) that did not respond to the treatment and were diagnosed with BKV kidney disease by kidney biopsy, including 2 patients with kidney transplant failure who had to undergo dialysis. In the group with active BK infection, after 6 months there was clearly kidney damage, shown by a sudden increase in blood creatinine. Conclusion: BK virus infection cause allograft dysfunction and graft loss. The management of BKV infection in renal transplant recipients is not yet clearly defined. However, early recognition of urological sequelae and modification of immunosuppressive therapy are essential to ensure adequate long - term function of these allografts. Currently, there is no specific drug to treat BKV, some drugs have supportive effects but are not very effective, have many side effects or are expensive such as IVIG, quinolones, leflunomide, cidofovir.