The presence of congestive heart failure can complicate the management of patients who undergo mechanical ventilation. Mechanical ventilation by itself affects the pathophysiology of congestive heart failure by decreasing both the venous return to the heart and cardiac afterload, both of which are well described. In addition, there are other ventilator cardiopulmonary interactions that are less well studied, but may also palliate the severity of heart failure. Withdrawal of mechanical ventilation during weaning reverses the beneficial effects on congestive heart failure of the ventilator. In patients with a low cardiac reserve, it can precipitate myocardial ischemia and worsen heart failure. Patients with poor left ventricular reserve may thus fail weaning attempts despite adequate lung mechanics. Aggressive treatment tailored to the severity of congestive heart failure can facilitate weaning from mechanical ventilation. Monitoring during weaning should be focused on clinical, biochemical, and imaging data that collectively represent the earliest indicators of decompensating heart failure. Treatment strategies include protocol driven weaning and increasing use of noninvasive positive pressure breathing after extubation.