Olefins are produced in the petrochemical industry by steam cracking of parrafins, followed by repeated compression and distillation to separate the complex vapour mixtures. The second step is considered to be a highly energy-intensive process and have been extensively studied for possible replacements. The use of membranes has been the focal point of research as a new means of olefin/paraffin separation due to its lower operating and capital costs. In this article, a comprehensive review is presented for the application of polymeric membranes in light olefin/paraffin separation. It covers all types of membrane materials starting from the conventional polymers to more advanced ones such as polyimide and copolyimide membranes. Permeation and separation characteristics of all polymeric membranes are summarized and discussed in great details. (C) 2011 Elsevier B.V. All rights reserved.