Here, the direct incorporation of photochromic WO 3 nanoparticles is investigated in a matrix of polymethyl methacrylate (PMMA) by bulk radical polymerization for the fabrication of plastic optical fibers (POFs). All the prepared composites, from preforms to 1D single fibers and 2D fabrics, are thoroughly investigated, leading to insight into their thermal, morphological, and photochromic properties (coloring/bleaching amplitudes and kinetics). It is found that the preforms exhibit partially irreversible photochromic behavior, whereas the single fibers proved to be effectively reversibly photochromic through a degradation of transmission signal upon UV irradiation and a full recovery under dark conditions. The as-prepared PMMA plastic fibers, both undoped and doped, show good homogeneity without any imperfections or contamination. The WO 3 nanoparticles play a dual role as intrinsic and extrinsic absorption centres leading to higher transmission losses. Finally, a handmade textile woven with a bundle of doped fibers is presented. The proposed 1D single fibers and 2D fabrics demonstrate their great potential as novel hybrid inorganic-organic materials in the domain of flexible UV-sensors and photochromic smart textile with improved color stability and lifetime.