BK polyomavirus (BKV) as a member of polyomavirus family is prevalent in the human population. BKV persists in renal tissue after asymptomatic infection in childhood. The reactivation of BKV in renal transplant recipients sometimes can lead to BKV associated nephropathy. BKV isolates are classified into four serologically distinct subtypes. Present study was carried out to investigate the distribution pattern of BKV subtypes in Iranian Turkish renal transplant recipients.Urine samples from 12 kidney transplant recipients infected with BKV were analyzed by RFLP-PCR technique for classification of subtypes.Our analysis showed that all samples were infected with BKV type I. BK virus types II, III, and IV were not detected in our patients.Based on the results of the present study, BKV subtype I was the most frequently detected subtype in renal transplant recipients. To our knowledge, the present study provides the first data regarding distribution of BKV subtypes in Iranian renal transplant recipients.