Following the publication of several landmark trials, there has been a significant increase in the cardiac device implantation. Within this population there are a number of patients who have pre-existing cardiac devices that have been placed for a number of different conditions. While the usual approach is to remove the existing unit and replace it with a new device with the removal or capping of existing lead systems, this practice often sacrifices an existing unit that still possesses good battery longevity. We explored the possibility of separating the pacing and defibrillating functions by implanting a new device on the top of the old device in a 'piggy-back fashion'. We report a series of four cases (with various indications) with differing combinations of devices. The procedure was performed safely in every one of them, and no device-device interaction was noted. Combining the new with existing units in a 'piggy-back' manner may be a safe and cost-effective technique in the selected cases.