We report on two patients treated with cardiac resynchronization therapy, in whom early (intra-operatively, 64-year-old man) and late (4 months post-operatively, 57-year-old woman) instability of the left ventricular (LV) lead occurred. In order to stabilize the electrodes, stents were deployed in both patients within the coronary sinus, into the space between the lead and the wall of the vein effectively pinning the lead to the wall. During 3 and 5 months of follow-up, the electrodes remained stable and allowed for successful resynchronization in both cases. Stenting within the coronary sinus seems to be a safe method for LV lead stabilization, which can substantially increase the success rate of resynchronization therapy. This new approach, although promising, has to prove its safety and should not be practised routinely until long-term follow-up data are available.