Using a new method for the isolation of released mother cell walls of Chlorella fusca, the biosorption of cadmium, copper and lead by purified cell wall isolates and whole cell suspensions was comparatively characterized. In all cases whole cells accumulated more metal ions than isolated cell walls. Both the Langmuir and Freundlich isotherm models were suitable for describing the short-term adsorption of cadmium, copper and lead by cell walls and the cadmium and copper adsorption by whole cells. However, neither model could sufficiently explain the lead accumulation by whole cells. The feasibility of a practical use of whole cells or isolated cell walls as biosorbents is discussed.