Abstract Pediatric R‐Tx patients are at high risk of developing EBV primary infection. Although high DNA replication is a risk factor for PTLD, some patients develop PTLD with low viral load. In this retrospective single‐center study including all pediatric patients having received R‐Tx (2003‐2012 period), we aimed to identify risk factors for uncontrolled reactions to EBV (defined as the presence of a viral load >10 000 copies/mL or PTLD). A Cox proportional hazard model was performed. A total of 117 patients underwent R‐Tx at a mean age of 9.7 ± 5.3 years, 46 of them being seronegative for EBV at the time of R‐Tx. During follow‐up, 54 patients displayed positive EBV viral load, 22 of whom presenting with primary infection. An uncontrolled reaction to EBV was observed in 24 patients, whilst 4 patients developed PTLD. Univariate and multivariate analyses suggested the following risk factors for an uncontrolled reaction: age below 5 years, graft from a deceased donor, ≥5 HLA mismatches, EBV‐seronegative status at the time of R‐Tx, and a secondary post‐Tx loss of anti‐EBNA. Monitoring anti‐EBNA after R‐Tx may contribute to the early identification of patients at risk for uncontrolled reaction.