The novel synthesis of EDTA-modified chitin/cellulose composite fibers is accomplished using dimethyl sulfoxide as the solvent, and the absorptive ability of the fibers for metal ions is examined by measuring absorption isotherms at different pHs. For some metal ions, the modified fibers show improved absorption powers compared with the parent fiber material. These composite fibers may be a reusable medium for metal ion removal and concentrations from an aqueous matrix.