Congestive heart failure is an uncommon complication of pregnancy with potentially life-threatening consequences. Peripartum cardiomyopathy is a disease of unknown cause in which severe left ventricular dysfunction occurs during late pregnancy or the early puerperium. In the past, the diagnosis of this entity was made on clinical grounds; however, modern echocardiographic techniques have allowed more accurate diagnoses by excluding cases of diseases that mimic the clinical symptoms and signs of heart failure. Risk factors for peripartum cardiomyopathy include advanced maternal age, multiparity, African descent, twinning, and long-term tocolysis. An extensive search for the causes of peripartum cardiomyopathy has been unrevealing. Treatment includes digitalis, diuretic agents, and vasodilators. Anticoagulation is strongly recommended, especially if ventricular function is persistent. The prognosis of peripartum cardiomyopathy is related to the recovery of ventricular function. Caution is advised in recommending subsequent pregnancy, especially if left ventricular dysfunction is persistent.