High-performance poly(ether ether ketone) (PEEK) fibers were prepared by melt-spinning in the presence of thermotropic liquid crystalline poly(aryl ether ketone) copolymer (FPAEKLCP). The rheological and mechanical properties, birefringence, orientation, and crystallization of the resulting PEEK/FPAEKLCP fibers were characterized by using a melt flow indexer, capillary rheometer, single fiber electronic tensile strength tester, polarized light microscopy (PLM), and wide-angle X-ray diffraction (WAXD), respectively. The results indicate that the melt viscosity of PEEK significantly reduced by introducing FPAEKLCP, followed by the improvements in the spinnability and the quality of as-spun fibers. The tensile properties of PEEK/FPAEKLCP fibers mainly depend on the content of FPAEKLCP, drawing temperature, drawing ratio, and annealing processes. Moreover, the tensile strength and modulus of PEEK/FPAEKLCP fibers are obviously higher than those of neat PEEK fibers under the same processing conditions. This should be attributed to an enhancement in the orientation and crystallization of PEEK compounded with FPAEKLCP. (C) 2013 Wiley Periodicals, Inc.