30 patients with severe congestive heart failure (NYHA IV) unresponsive to medical management were treated by continuous hemofiltration (CHF). 57% of patients received arteriovenous CHF and 43% of patients venovenous, machine assisted CHF over 95 +/- 31 hours. A reduction of body edemas was achieved. The removal of body fluid by CHF between 2 and 40 kg led to a reduction of body edemas and short-term clinical improvement. Furthermore CHF treatment induced hemodynamic improvement with a reduction of central venous pressure (18 +/- 6 cm H2O pre CHF vs 8 +/- 4 cm H2O post CHF p less than 0.01) and a reduction of left ventricular filling pressure (22 +/- 6 mm Hg vs 14 +/- 5 mm Hg, p less than 0.01), while the left ventricular ejection fraction remained unchanged. Patients with low serum sodium levels (less than 132 mval/l) benefited most. While 28/30 of patients has short-term clinical improvement between 2 and 8 weeks, 38% of patients had long-term benefits.