Sorption and pervaporation of benzene/cyclohexane mixtures were studied by using poly(vinyl chloride) (PVC) polymer. The effects of composition of benzene/cyclohexane mixture and temperature on sorption and pervaporation characteristics were determined at 30, 40, and 50 degreesC for the membranes containing 8 wt% PVC polymer. Liquid feed composition effects on the flux and the selectivity were determined for two different membranes at 30 degreesC. The membranes that were prepared from the solutions containing 4 wt % and 8 wt % PVC polymer have thicknesses of 30 mum and 50 mum, respectively. Membrane thickness changes with polymer content as expected. Total sorption increased with increasing concentration of benzene. Increasing the concentration of benzene resulted in increasing flux as well as decreasing selectivity also. Fluxes were increased and selectivity decreased with increasing temperature. The selectivity was not affected significantly with varying amounts of polymer in the casting solution but the flux decreased with increasing amount of polymer in the casting solution.