In this article, we provide an overview of recent progress in toughening and damage self-healing of polymer-matrix composites (PMCs) reinforced with electrospun nanofibers at interfaces with an emphasis on the innovative processing techniques and toughening and damage self-healing characterization. Because of their in-plane fiber architecture and layered structure, high-performance laminated PMCs typically carry low interfacial strengths and interlaminar fracture toughnesses in contrast to their very high in-plane mechanical properties. Delamination is commonly observed in these composite structures. Continuous polymer and polymer-derived carbon nanofibers produced by electrospinning, solution blowing, and other recently developed techniques can be incorporated into the ultrathin resin-rich interlayers (with thicknesses of a few to dozens of micrometers) of these high-performance PMCs to form nanofiber-reinforced interlayers with enhanced interlaminar fracture toughnesses. When incorporated with core-shell healing-agent-loaded nanofibers, these nanofiber-richened interlayers can yield unique interfacial damage self-healing. Recent experimental investigations in these topics are reviewed and compared, and recently developed techniques for the scalable, continuous fabrication of advanced nanofibers for interfacial toughening and damage self-healing of PMCs are given. Developments in the near future in this field are predicted. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2225-2237, 2013