Pervaporation, a membrane-based separation technique, is proposed as a potential replacement for the vacuum distillation process which is normally used for the dehydration of glycerol-water mixtures. Separation characteristics of glycerol-water mixtures containing a trace amount of water by using a water-selective cellophane membrane an studied. Experiments show that the membrane is selective toward water, and pure water is obtained as the permeant. Thus, the selectivity coefficient is infinite. However, the rate of permeation of water is solely controlled by the liquid-phase mass transfer boundary layer resistance due to the very high viscosity of glycerol. Accordingly, increased agitation and temperature cause considerable enhancement of flux. On the other hand, the presence of salt in the feed mixture significantly reduces the rate of permeation. An unsteady-state model, that includes various process parameters, has been developed for prediction of the process output. The model prediction fits satisfactorily with the experimental observations of the present study.