Background <p>Central venous catheterization is a common procedure that enables the application of drugs and fluids, can assist in hemodynamic monitoring or serve as vascular access for extracorporeal therapies. Central venous catheter insertion is generally safe, but complications do occur.</p> Case presentation <p>We present a patient with a kidney transplant in the right iliac fossa and septic shock who was in need of urgent catheter insertion. The right femoral vein was chosen as the site of insertion. There were no major complications during the insertion and no problems with the use of catheter afterwards. Two weeks after the insertion we incidentally discovered that the tip and a large portion of the catheter had been inserted into the renal vein of the transplanted kidney. The position of the catheter was changed by the radiologist with no clear harm to the transplanted kidney.</p> Conclusions <p>Femoral central vein catheter malposition into the renal vein of a transplanted kidney is to our knowledge very rare and has been reported only once. This case report highlights the importance of considering altered anatomy in kidney transplant recipients and emphasizes the importance of imaging and caution in such cases to prevent potentially serious complications.</p>