In the present study, vapor permeation and pervaporation of aqueous 2-propanol mixtures were investigated using Torlon (R) poly(amide imide) as a membrane material. Torlon membranes preferentially permeated H2O from aqueous 2-PrOH mixtures both by vapor permeation and pervaporation. Diffusion experiments led to the conclusion that both solubility selectivity and diffusivity selectivity showed a preference for H2O. Solubility selectivity is by far the dominant factor governing permselectivity, and as a result, Torlon membranes showed permselectivity toward water in vapor permeation and pervaporation. The present study showed that Torlon (R) poly(amide imide) is a membrane material potentially applicable to the dehydration of water miscible organics.