With the aim of treating with short sessions even chronic uremic patients with cardiovascular instability, we have developed our previous findings about paired filtration dialysis (hemofiltration-hemodialysis in series) by a method we call high-efficiency paired filtration dialysis (HEPFD). We have treated with this method for 6 months 6 chronic anuric uremic patients previously treated for 6 months with hemofiltration (HF) because of their cardiovascular instability. By comparison with HF, HEPFD shows much higher clearances of small molecules with consequent significant decrease of their predialytic values, improvement of Kt/V value, lower beta 2-microglobulin clearance (its predialytic value remains unchanged), and the same tolerability. HEPFD allows short, efficient, and well-tolerated treatments even in patients with cardiovascular instability.