Patients with heart failure and profound cardiogenic shock, who are unresponsive to vasopressors and intra-aortic balloon pump insertion, have few options except for mechanical cardiac support with a ventricular assist device. The TandemHeart is a new assist device that may be percutaneously or surgically inserted. We review techniques for percutaneous and intraoperative placement of the TandemHeart, including detailed descriptions of its insertion. Additionally, we present the most common complications associated with the percutaneous or operative approaches and suggest ways to avoid these complications. Whether placed percutaneously or surgically, the TandemHeart can provide adequate hemodynamic support for heart failure patients. If the device is placed by surgeons in the operating room, there must be strict adherence to protocols and de-airing techniques. Complications may occur with either insertion technique, so knowledge of the most common types of complications and their prevention is necessary.