The cytoskeleton underlying the membrane of erythrocytes is thought to control changes in cell shape such as the diskocyte to the echinocyte. Since the binding of lectins to the transmembrane protein glycophorin blocks the cell shape change, we have proposed that the cytoplasmic end of glycophorin is linked to the cytoskeleton. Here we show that the cytoskeletal protein known as band 4.1 specifically associates with the cytoplasmic domain of glycophorin on inside-out erythrocyte membrane vesicles and also with glycophorin reconstituted into phosphatidylcholine vesicles. The binding of band 4.1 to glycophorin is saturable and inhibitable by antibodies which bind specifically to the cytoplasmic domain of glycophorin. We therefore believe that band 4.1 protein provides the link between glycophorin and the cytoskeleton.