The effect of slip velocity at a membrane surface is studied in detail for a tubular membrane system. A second-order perturbation solution of the equations of motion is found to be very satisfactory. The results are compared with those of the channel flow system reported earlier. As in the case of channel flow system, the effect of slip coefficient on concentration polarization is identical to that of Péclet number-it augments diffusive transport of solute molecules from the membrane surface to the bulk solution. © 1979.