Superficial urothelial tumours of the bladder are more frequent and more often at higher risk of progression and recurrence in renal transplant recipients. When conservative treatment of these tumours is indicated, BCG instillations are recommended. However, immunosuppression of renal transplant recipients constitutes a classical contraindication to BCG therapy. Some authors have nevertheless used BCG instillations in renal transplant recipients. The authors reviewed the use of BCG in renal transplant recipients by studying the effects of immunosuppression on the mechanisms of action of BCG and the various clinical experiences reported in the international literature.