A new coated charcoal for hemoperfusion in uremia was investigated in 14 patients with end stage renal disease who underwent hemoperfusion or combined hemodialysis-hemoperfusion (39 seances). Investigations concerned removal of small molecules, coagulation and hematological status and amino acids and some hormones equilibrium. Clinical observations were also made in all patients. The methacrylate-coated charcoal enabled the removal of "toxins" up to 5000 daltons and the total solute removal did not significantly differ from previous hemoperfusion systems. However, the new coating membrane showed improved biocompatibility, in terms of clinical side effects and/or platelet and fibrinogen alterations.