Lengthening the spacer of N-acetyl glucosaminyl oligoethoxy cholesterol neoglycolipids from one to seven ethoxy units modified neither the neoglycolipid incorporation into liposomes nor the liposome sizes. Moreover, lengthening the spacer from three to seven units increased the 5(6)-carboxyfluorescein leakage from mixed liposomes. These neoglycolipid-induced disturbances in membrane permeability were corroborated by determining their haemolytic activities.