Addition of hydrophobic adsorbents such as activated carbon into polymeric membranes increased the sorption capacity for 1,1,1-trichloroethane and the trichloroethane permeability of the membranes used in the pervaporation mode. Water permeability also increased for all filled membranes due to increased water sorption, The intrinsic separation factor for trichloroethane, however, increased only for membranes filled with activated carbon. It did not change for membranes filled with a carbonaceous adsorbent made by polymer pyrolysis, The solubility of trichloroethane in the filled membranes was measured directly by a "purge and trap" method, The trichloroethane diffusivities in the filled membranes were calculated from the solubility and permeation data or determined by desorption experiments. It was shown from these results that the enhancement in trichloroethane selectivity and permeability for the activated carbon-filled membrane was mainly due to the increase of trichloroethane solubility.