MCS (mechanical circulatory support) significantly modifies the hemodynamic balance of implanted patients with an unavoidable impact on lung function. MCS patients are critically ill and are particularly exposed to all possible pulmonary complications in the ICU. However, specific complications of MCS exist. The most specific and common pulmonary complication in short-term MCS is induced VA ECMO (veno-arterial extracorporeal membrane oxygenationVeno-arterial extracorporeal membrane oxygenation (VA ECMO)) lung edemaLung edema, which is associated with significantly worse outcomes and requires systematic active steps to prevent its occurrence. Other complications include lung ischemia due to the loss of the transpulmonary gradient, among other causes. Lung ischemia is directly involved in the syndrome of acute lung injury occurring after implantation of a long-term MCS in patients who are under VA ECMO. Chronical complications of long-term MCS include functional pulmonary limitations mainly due to the size of the device in the thorax and to the surgical consequences on the diaphragmatic mechanics. RVADs (right ventricle assisting devices) are more directly related to pulmonary hemodynamics than the LVADs (left ventricle assisting devices). Uncontrolled RVAD output produces pulmonary hypertension and creates pulmonary edema and hemorrhage in the process. This chapter is an overview of the specific pulmonary complications following MCS.