A new preparation method for polymer inclusion membrane (PIM) was developed. The preparation method-called post-treatment method-is very convenient to prepare a hollow fiber PIM. Using this method, a commercial cellulose triacetate (CTA) hollow fiber membrane can be easily converted into a hollow fiber PIM. Thus, a CTA hollow fiber membrane was allowed to swell in 2-nitrophenyln-octyl ether (NPOE) in the presence of chloroform as a solvent for CTA and N,N,M,M-tetraoctyl-3-oxapentane diamide (TODGA) as a carrier. After evaporating chloroform, a hollow fiber PEA containing NPOE and TODGA was obtained. The result of the transport experiment of cerium(III) ions using the hollow fiber PIM showed that cerium ions were effectively transported from the feed solution to the strip solution through the hollow fiber PIM, indicating that the hollow fiber PIM was successfully prepared using the post-treatment method. (c) 2006 Wiley Periodicals, Inc.