A 68-year-old man, 54 months after having been implanted with a biventricular device, underwent successful extraction of the malfunctioning left ventricular (LV) lead using mechanical dilation. During LV lead reimplantation, venography documented stenosis of the coronary sinus (CS). To overcome the obstacle, balloon angioplasty was performed and a LV lead was then inserted into a lateral tributary of the CS. The procedure was complicated by local infection and, after 2 months, removal of the entire unit became necessary. During controlateral device implantation, a second angioplasty was carried before insertion of the new LV lead because, in the meantime, restenosis had developed in the CS.