An investigation has been made of the drug removal properties and blood compatibility of activated charcoal and resin haemoadsorbents . The adsorbents were Norit RBX1 peat-based extruded charcoal, spherical charcoal as used in the Sorin Biomedica Detoxyl 2 column and 2 cross-linked polystyrene-based macroreticular resins. Drug removal properties were assessed in terms of in vitro adsorption efficiency of each adsorbent for 11 different drugs. The blood compatibility of the charcoals and macroreticular resins was evaluated in an in vitro haemoperfusion circuit by measuring the changes in platelet and leucocyte levels in human blood caused by contact with the adsorbent. The results of the investigation indicate advantages in using spherical charcoal haemoadsorbents .