In this study we have covalently linked the anticoagulant warfarin to polyfunctionalized fullerenes. The objective was to explore the possibility of modifying the biological profile of a drug by covalent binding to functionalized fullerene. We have chosen warfarin as a model compound because it a widely used drug. We have analyzed the stability in vitro of the conjugates and found that the drug is released from the carbon support only after incubation in mouse plasma.