Swan-Ganz catheters were used in the care of 3 toxemic parturients who developed pulmonary edema. Initial pulmonary capillary wedge pressures (PCWP) ranged from 22 to 33 torr, indicating decompensated left ventricular failure. Simultaneous central venous pressures were essentially normal. Isolated left ventricular dysfunction was primarily the result of increased afterload and responded to afterload reduction with arteriolar vasodilators. Continued measurement of PCWP permitted the titration of afterload reduction to the levels associated with normal ventricular filling pressures and volume. Since the relationship between right and left ventricular pressures may be distrurbed in cardiogenic pulmonary edema, the Swan-Ganz catheter is the preferred method of hemodynamic monitoring in toxemic patients who develop cardiopulmonary dysfunction.