Six patients with severe congestive heart failure were treated with nitroprusside intravenously. Four of the six patients showed salutary responses and were successfully weaned from the NP with marked resolution of symptoms. No adverse side effects were observed. These four patients and one additional child (who did not receive NP) were treated with prazosin by mouth in addition to digoxin and diuretics daily. Two of these patients are entirely symptom free, and additional child is moderately improved, and the fourth patient has shown minimal symptomatic improvement. Despite the severity of their pretherapy symptoms, only one patient has died while receiving oral vasodilator therapy. This preliminary study suggests that afterload reduction may be life-saving in children who are virtually moribund because of congestive heart failure. This improvement can be maintained with oral vasodilator therapy and continuation of classic anticongestive therapy. However, afterload reduction has no effect on the underlying disease. Confirmatory studies are essential before this experimental mode of therapy is accepted for routine use in infants and children.