A rapid method suitable for the direct titrimetric determination of calcium in icteric sera is presented. The major portion of serum chromogens are oxidized to colorless products by either a mixture of hydrogen peroxide and potassium ferricyanide or by sodium hypochlorite. Ethylenediamine tetraacetic acid (EDTA) is the titrant used and either calcein or Cal-Red is suitable as the specific calcium indicator. Results compare favorably with those obtained by the method of Clark and Collip.