Earlier work showed that (enzymatic) hydrolysis of inner leaflet phospholipid of the bilayer of the erythrocyte membrane increases the rate of the dissociation of cytoskeletal proteins which takes place at low ionic strength. It has now been established that this increased rate results from the presence in the membrane of hydrolysis products, the lysophospholipids. The effects of a number of other substances on the dissociation were examined in view of the possibilities (a) that the association in normally functioning cells depends on an appropriate concentration of some substance, and (b) that the widespread physiological effects of local anesthetics are due to modification of bilayer-cytoskeleton interactions. Only two of the substances examined, neither of them anesthetics, increased the dissociation rate of the cytoskeletal proteins. One is phosphoryl choline, which is structurally related to the polar groups of the lysophospholipids. The other is 2,3 diphosphoglycerate (DPG), which is normally present in red cells. Additional studies are necessary to determine if DPG affects bilayer-cytoskeletal association under physiological conditions.