Hexagonal single-crystal perovskite-like (A(3)B(8)O(21)) nanofibers were synthesized via the electrospinning technique. High-resolution transmission electron microscopy imaging showed that each single nanofiber is composed of several interconnected small crystals. The selected-area electron diffraction analysis reveals a single crystalline nature of the fabricated nanofibers. The fabricated nanofibers showed surface plasmon resonance characteristics. Theoretical and computational calculations using the Mie-Gans theory were performed to investigate the plasmonic and optical properties of the obtained nanofibers, which were also confirmed experimentally and compared to gold nanoparticles. The fabricated nanofibers were tested as novel substrate materials for surface-enhanced Raman spectroscopy, showing exceptional performance.