A simple and continuous approach for fabricating magnetic polyacrylonitrile nanofibers (MNFs) with the diameter of about 200 nm has been developed by combining surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization and coaxial electrospinning. The RAFT polymerization of acrylonitrile was carried out on the surface of RAFT agent immobilized Fe3O4 nanoparticles. The room-temperature saturation magnetizations of the prepared MNFs can be easily adjusted. In addition, the aligned fibers can be conveniently obtained via magnetic electrospinning using a specially designed fiber collector. (C) 2013 Elsevier Ltd. All rights reserved.